BAKFlip MX4 specs
| Brand | BAK |
|---|---|
| Cover type | Hard folding: Hard folding; panels fold to the cab and stand upright on prop rods |
| Material | Aluminum panels over a high-density core, matte finish |
| Lock | Locks with tailgate. Automatic latches engage on closing; the cover is secured by your locked tailgate (no separate key). |
| Security level | Level 2: hard, tailgate-locked (our grouping) |
| Bed access | 100% bed access. BAK claims 100% bed access: the folded stack stands upright behind the cab on prop rods, and you can drive fully open. |
| Drive with it open | Yes |
| Install | No drilling on most trucks; frame rails clamp inside the bed rails. BAK claims a one-person install in under 30 minutes. |
| Load rating | 400 lb evenly distributed (maker claim) |
| Profile | Low profile, at or near the bed rails |
| Weather sealing | Edge-to-edge rubber seals with a built-in drainage system (drain tubes). |
| Bed racks | etrailer confirms the TruXedo Elevate rack fits; BAK also sells an MX4 TS version with T-slot rails. etrailer warns the Thule TracRac SR can interfere with the seals. |
| Warranty | 5 yr |
| Made in | USA (per etrailer's listing of the maker specs) |
| Fitment we checked | 2021–2027 Ford F-150 5'7" bed (67.1"), incl. Raptor and Lightning (part 448339) |
| Price tier | $$$ Premium ($900–$1,600), about $1,199.99 for this fitment when checked. See Amazon for today's price. |
- The 400 lb load rating, 1/2-inch panels, drain tubes, 5-year warranty and USA manufacture come from etrailer's reproduction of BAK's specs for the Ram 1500 version (checked Nov 12, 2026). The F-150 Amazon listing's details table shows a 'Weight Capacity Maximum' of 54.9 lb, which looks like a data-entry error; we use the maker figure.
- BAK sells an MX4 EZ-Lift version (2026 listings) and an MX4 TS with T-slot rails for racks. Both are separate listings with their own prices.
- Ram 1500 owners: this part doesn't fit the Multi-Function (split) tailgate; check the RamBox (RB) version if you have one.
Fitments we checked
Each truck and bed is a separate Amazon listing. Prices are what Amazon showed on November 12, 2026, not live. Always confirm with the listing's fitment tool before you buy.
| Truck and bed | Notes | Price |
|---|---|---|
| Ford F-150 2021–2027, 5'7" bed | Part 448339 (our representative listing) About $1,199.99 when checked | Check price |
| Ford F-150 2021–2027, 6'7" bed | Part 448337 About $1,271.15 when checked | Check price |
| Ram 1500 2019–2027, 5'7" bed | Part 448227; not for the Multi-Function (split) tailgate About $1,222.12 when checked | Check price |
| Silverado/Sierra 1500 2019–2027, 5'10" bed | Works with MultiPro/Flex tailgates; not the CarbonPro bed About $1,199.99 when checked | Check price |
| Toyota Tacoma 2024–2027, 5' bed | Part 448446 About $1,249.99 when checked | Check price |
| Toyota Tacoma 2016–2023, 5' bed | Part 448426; for beds with the OE track system About $1,277.98 when checked | Check price |
| Toyota Tundra 2022–2027, 5'7" bed | Part 448440 About $1,233.73 when checked | Check price |
| Ford Ranger 2024–2025, 5' bed | Part 448342 About $1,249.99 when checked | Check price |
| Ford Ranger 2019–2023, 5'1" bed | Part 448332 About $1,282.02 when checked | Check price |
| Colorado/Canyon 2023–2027, 5'2" bed | Part 448146 About $1,220.19 when checked | Check price |
Specs are compiled from maker copy on Amazon and at the retailer etrailer, plus independent tests, and may change between production runs. Not sure of your bed? Use the bed size finder.
BAKFlip MX4 Hard Folding Tonneau Cover video review
Video by Zach Attack Customs on YouTube. Independent creator content, shown as a reference. It is not part of our scoring.
The BAKFlip MX4 is a hard folding tonneau cover with aluminum panels that fold toward the cab and stand upright on prop rods, so the whole bed can open. It’s our top-rated cover overall and the one we’d point most owners to first. The 2021–2027 Ford F-150 5’7” bed listing (part 448339) was $1,199.99 on Amazon on November 12, 2026, and other trucks ran up to about $1,282. We haven’t tested the MX4 ourselves; this review is built from BAK’s specs, the Amazon listings for each truck and owner feedback. Not sure which bed you have? The bed size finder will tell you, and our best tonneau covers of 2026 shows where the MX4 sits against everything else.
Who the MX4 is for (and who should skip it)
It’s for owners who want a lockable hard cover that still gives back the full bed. That makes it a good fit for anyone who hauls a mix of tools, groceries and the occasional tall load. It also has the biggest owner base of any hard folder we track: 1,839 ratings on the Silverado listing and 1,285 on the Ram, averaging 4.2 stars.
Skip it if you need the cover to lock on its own. A RetraxPRO MX or the UnderCover Elite have their own keys. Skip it on a tight budget too: the Gator EFX costs about half as much and keeps most of the benefits, minus full bed access.
Security and locking
The MX4 latches automatically the moment you close it, with no separate locking step. BAK calls the latch system patented. The panels are aluminum over a high-density core, which BAK says is stronger than single-layer construction. On our three security levels that makes it a level 2 cover: hard panels that stop casual theft, held shut by your tailgate lock. If your truck’s tailgate doesn’t lock, add a Pop & Lock tailgate lock before you trust the bed with anything valuable.
Access and everyday use
This is where the MX4 earns its price. Fold the panels toward the cab and the stack can stand upright behind the cab on prop rods. BAK claims 100% bed access and says you can drive fully open. Our bed access calculator allows about 6 in for an upright stack, which leaves roughly 91% of a 5.5 ft bed open to the sky. Standing panels block the rear window, so expect to rely on mirrors and the camera when it’s up.
Weather sealing
BAK lists edge-to-edge rubber seals and a built-in drainage system with drain tubes. No independent water test of the MX4 that we could find has been published. As with any folder, route the drain tubes properly and keep the seals clean. Our guide to whether tonneau covers are waterproof explains what to expect.
Install
BAK says one person can install it in under 30 minutes, with no drilling on most trucks: the frame rails clamp inside the bed rails. Those are maker claims. Allow longer the first time and follow the seal and clamp instructions carefully. Our install guide covers the general steps.
Fitment notes
We checked MX4 listings for the 2021–2027 F-150 (5’7” and 6’7” beds), 2019–2027 Ram 1500 5’7”, 2019–2027 Silverado/Sierra 1500 5’10”, Tacoma (2016–2023 and 2024–2027, 5 ft), 2022–2027 Tundra 5’7”, Ranger (2019–2023 and 2024–2025) and 2023–2027 Colorado/Canyon. Watch these details:
- Ram 1500: the standard part doesn’t fit the Multi-Function (split) tailgate, and RamBox trucks need the RB version.
- Silverado/Sierra: the 5’10” part works with MultiPro/Flex tailgates but not the CarbonPro bed.
- 2016–2023 Tacoma: listings are for beds with the OE track system.
Confirm your part number with the listing’s fitment tool.
What you’ll need beyond the box
- A tailgate lock if your truck lacks one (see above).
- A bed mat stops cargo sliding into the bulkhead under a closed cover. For the F-150 5.5 ft bed, the Rough Country bed mat is about $100 and the Husky bed mat about $160.
- A bed rack, if you carry gear up high. The RealTruck Elevate FS base rack is designed for RealTruck covers, but its listing says T-slot covers, so check fitment against the MX4 TS. Our covers with a bed rack guide explains the options.
More on the accessories page.
Reliability and warranty
BAK backs the MX4 with a 5-year warranty, and etrailer’s spec reproduction says it’s made in the USA. BAK also sells an MX4 EZ-Lift version and the MX4 TS with T-slot rails as separate listings, each with its own price.
Bottom line
The MX4 does the most things well at once: hard panels that latch on their own, a fold that stands upright for full access, a 400 lb rating, a 5-year warranty and a long owner record. At about $1,200 it isn’t cheap, and its security is only as good as your tailgate lock. If that’s fine, it’s the cover we’d buy. Check the MX4 price, or see how it compares with BAK’s hard roll-up in BAKFlip MX4 vs Revolver X4s.
Accessories that pair with the BAKFlip MX4
Cover care, bed racks, mats and cargo gear sold on Amazon. Most bed and floor products are vehicle-specific: the fitment shown is the listing we checked, so search the same product for your truck if yours differs.
- Bed rackRealTruck Elevate FS Base Rack (1119034)From RealTruck
A low bed rack that leaves the cover working underneath. Rated 750 lb static, 500 lb on-road and 250 lb off-road per the listing, with T-slots for bikes, kayaks and rooftop tents. Per the listing, it fits RealTruck T-slot-equipped covers (such as BAK's TS versions) and most inside-mount soft roll-ups. Standard non-TS hard covers need T-slot rails. Check RealTruck's fit guide for your exact cover.
- Bed rackYakima OverHaul HD adjustable truck bed rack (8001151)Works with any cover
Height-adjustable towers with T-slots and SKS locks, rated 500 lb on-road and 300 lb off-road per the listing, for rooftop tents, ladders and boats. The Amazon listing doesn't state tonneau-cover compatibility. Check Yakima's fit guide for your truck and cover before buying.
- Cargo managementKeeper ratcheting cargo bar, 40–70 in (05059)Works with any cover
Pins groceries and gear against the bulkhead or tailgate so nothing slides around under a closed cover. It sits below rail height, so the cover closes over it. 40–70 in span; measure between your bed walls at the height you'll use it.
- Cargo managementRhino USA ratchet straps, 1 in × 15 ft (4-pack)Works with any cover
Tie-downs for loads strapped to a bed rack, or tall cargo you haul with a roll-up or folding cover open.
- Cargo managementMigaven heavy-duty truck bed cargo net, 4 × 6 ftWorks with any cover
The fallback when a load sticks up past the rails and the cover has to stay open: a stretch net over the bed keeps loose items in.
- Cargo managementRough Country slide-out truck bed cargo tray (10209)Works with any cover
Brings small items to the tailgate so you don't have to crawl under a cover to reach the front of the bed. Rough Country says the 4 in tray fits under any bed cover. Listing fitment: Trucks with a 5'7" or longer bed (tray is 62.3 × 23.6 × 4 in). Per the listing, fits beds 5'7" or longer; 5 ft midsize beds are too short.
- Cargo managementDECKED drawer system (XR7)Works with any cover
Two bed-length lockable drawers under a flat deck rated for 2,000 lb of cargo per the listing. Under a locking cover, it turns the bed into secure tool storage. Listing fitment: 2019–current Ram 1500 (DT) 6'4" bed, not RamBox. A drawer system raises the bed floor, which cuts the height left under a cover. DECKED sells a separate model for each truck and bed length.
- Bed matHusky Liners custom-fit rubberized bed mat (16008)Works with any cover
A rubberized mat with air-dry nibs underneath, so water that gets past a soft cover's seals can drain instead of sitting on the paint. Listing fitment: 2015–2026 Ford F-150 and 2022–2026 F-150 Lightning, 5'7" bed. Per the listing, it will not fit over a drop-in bed liner.
- Bed matRough Country heavy-duty rubber bed mat (RCM671)Works with any cover
A cheaper rubber mat that protects the floor and keeps cargo from sliding into the tailgate. Listing fitment: 2015–2027 Ford F-150, Lightning and Raptor, 5'7" (67 in) bed.
- Bed linerBedRug Classic bed liner (BRQ15SCK), charcoal greyWorks with any cover
A full-coverage foam-backed carpet-style liner for the floor, walls and tailgate: kneeling-friendly, and it stops cargo sliding around under a cover. Listing fitment: 2015–2024 Ford F-150 5'7" (5.5 ft) bed. Per the listing, the BRZSPRAYON install kit is required over a spray-in liner. If you run a clamp-on cover, make sure nothing sits on top of the bed rail where the clamps grip.
Compatibility checked November 2026. More in our truck bed accessories guide.
Featured in our guides
- The 8 Best Tonneau Covers of 2026: Ranked by Type, Truck and Budget
- The Best Tonneau Covers for the Ford F-150 (2021–2026): 7 Picks by Bed and Budget
- The Best Tonneau Covers for the Ram 1500 (2019–2026): 7 Picks, Plus RamBox and Split-Tailgate Fit
- The Best Tonneau Covers for the Silverado and Sierra 1500 (2019–2026): 7 Picks
