BAK Revolver X4S Tonneau Cover – Hard Folding Truck Bed Cover
The BAK X4S is a hard folding tonneau cover engineered for truck owners who need weather-tight cargo protection without sacrificing bed access. We built the X4S with powder-coated aluminum slats that fold completely open and rest flush against the cab, giving you full bed length when you need it. The cover installs with a no-drill clamp system that fits most full-size trucks, from F-150 and Silverado to RAM and Tundra.
Each panel locks independently, so you can open just one section or fold the entire cover back in seconds. The low-profile design sits less than an inch above the bed rails, maintaining your truck's clean look while improving aerodynamics. We back every BAK X4S with a five-year warranty covering materials and workmanship.
What makes the X4S stand out
Aluminum panel construction and finish
We manufacture the X4S panels from marine-grade aluminum alloy, then apply a matte black powder-coat that resists scratches and won’t fade in direct sun. Each slat is ribbed for additional rigidity, so the cover stays flat under highway wind without bowing or flexing.
The powder-coat process bonds the finish at a molecular level, which means it won’t chip like spray paint when you load cargo or wash the truck. We tested the coating through salt-spray cycles and UV exposure equivalent to five years of desert sun, and the finish held without discoloration. The same aluminum framework found in our Revolver X4S series carries over to every model, ensuring consistent strength across the lineup.
Fold-flat bed access in seconds
The four-panel design lets you fold the BAK X4S completely open and secure it against the cab, giving you unobstructed access to the entire bed. Each panel connects with aircraft-grade hinges that won’t bind or corrode, even after thousands of open-close cycles.
You can also open just the first panel for smaller loads, or fold back two or three sections depending on what you’re hauling. The rotary latches release with a quarter turn, and the spring-assisted hinges make lifting the panels effortless. When folded, the cover rests securely against the cab without sliding or rattling, so you can drive with it open on short trips.
No-drill clamp installation
We designed the X4S with a rail-mount system that installs without drilling into your truck bed. The clamps slide into place along the bed rails, then tighten with hand tools in about 30 minutes. The rails are pre-drilled and powder-coated to match the cover, and they sit flush with the bed lip for a factory-installed look.
Truck compatibility
The BAK X4S fits most full-size trucks with 5.5-foot, 6.5-foot, and 8-foot beds. We offer model-specific kits for Ford F-150, Chevrolet Silverado 1500, GMC Sierra 1500, RAM 1500, Toyota Tundra, and Nissan Titan. Each kit includes shims and spacers to account for bed-rail variations, so you get a tight seal even if your rails aren’t perfectly straight.
Other hard folding covers in the X4S lineup
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Common questions about the BAK X4S cover
Yes, the X4S works with most spray-in bedliners. The clamps are adjustable and include shims to account for the extra thickness. If your liner extends above the bed rails, you may need to trim it slightly at the clamp points for a flush fit. We recommend test-fitting the rails before final installation.
You can drive with the X4S folded open, and the hinges will keep it secured against the cab. We recommend using the included bungee straps for highway speeds to prevent wind lift. The cover is designed to stay in place, but the straps add extra peace of mind on long trips.
The aluminum panels are strong enough to support moderate snow loads without sagging. The ribbed design prevents pooling, and the powder-coat resists ice adhesion. In heavy snow regions, we suggest brushing off accumulation to reduce weight on the hinges. The weather seals remain flexible in cold temperatures and won't crack.
The X4S is compatible with most bed-rail accessories like tie-down anchors and cargo bars. The clamp system leaves the bed rails accessible, so you can still use stake pockets and D-rings. If you have an existing bed extender or bike rack, confirm it mounts to the tailgate rather than the rails.
The X4S is rated for 400 pounds evenly distributed across all four panels. The aluminum slats and hinges are reinforced to handle that load without flexing. We don't recommend standing or kneeling on a single panel, as that concentrates weight unevenly. For heavy rooftop cargo, consider adding a roof rack instead.
Loosen the clamps with a 10mm socket and the entire cover lifts off in one piece. The rails stay attached to the cover, so you don't have to disassemble anything. The whole process takes about five minutes. Store the cover flat or upright to avoid warping the panels.
The X4S can coexist with low-profile toolboxes that sit against the cab, as long as the box doesn't extend past the bulkhead. For bed racks, you'll need a rack system that mounts to the bed floor or stake pockets rather than the rails. Most over-the-rail racks will interfere with the cover's clamp system.