BAKFlip MX4 Hard Folding Tonneau Cover — Low-Profile Aluminum Truck Bed Cover
The BAKFlip MX4 is our premium hard folding tonneau cover engineered for truck owners who demand security and style. With a low-profile 40mm aluminum panel design, the MX4 sits flush with your truck bed rails for a streamlined look while protecting cargo from weather and theft.
We built the MX4 with heavy-duty aluminum panels that support up to 400 pounds when evenly distributed, so you can stand on the cover or load gear on top. The four-panel folding design gives you full bed access when open and locks securely at your tailgate. Installation takes about an hour with basic hand tools — no drilling required on most truck models.
MX4 specifications & design
Aluminum Panel Construction & Weather Protection
We manufacture the MX4 panels from industrial-grade aluminum with a durable powder coat finish that stands up to years of sun, rain, and road debris. Each of the four panels measures 40mm in profile height, creating a sleek, low-profile appearance that doesn’t compromise your truck’s aerodynamics or sight lines.
The panel edges feature dense foam weatherstripping that seals against your bed rails and between panels. This weathertight design keeps rain, snow, and dust out of your cargo area even during highway driving or severe weather. The automatic latching system at each fold point ensures panels stay locked in place whether you’re driving with the cover fully closed or folded back for taller loads.
Folding Panel System & Bed Access
Four-Panel Folding Design
The MX4 divides into four equal aluminum panels that fold forward in pairs, giving you flexible cargo access. Fold back one or two panels to haul taller items while keeping the rest of your bed covered and secure. When you need full bed access, the entire cover folds completely forward and rests behind your cab.
Each panel locks automatically as you close it, and the rear panel integrates with your factory tailgate lock for theft protection. We designed the hinge system with stainless steel components that won’t rust or seize, even in harsh climates. The panels stay in position at any fold angle, so you can load gear without the cover slamming shut.
Installation & Truck Compatibility
We designed the MX4 for no-drill installation on most full-size truck models. The integrated rail system clamps directly to your bed rails using adjustable clamps — just position the rails, tighten the clamps, and drop the panels into place. Most truck owners complete installation in 60-90 minutes with basic hand tools.
The MX4 is available in vehicle-specific models engineered to fit Ford F-Series, Chevy Silverado, GMC Sierra, Ram, Toyota Tundra, and Nissan Titan truck beds. Each kit includes all necessary hardware, pre-assembled panels, and detailed instructions with photos. Our rail system adjusts to accommodate aftermarket bed liners and spray-in liners up to 1/4 inch thick.
Complete Your Truck Bed Setup
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Common Questions About the BAKFlip MX4
The 40mm measurement refers to how high the MX4 panels sit above your truck bed rails when installed. This low-profile design creates a sleek, aerodynamic appearance that sits nearly flush with your bed rails. The slim profile improves fuel economy compared to bulkier tonneau covers while maintaining full weather protection and security. It also ensures the cover doesn't obstruct your rear window view or interfere with most camper shells and cab-mounted accessories.
Yes, you can safely drive with one or two panels folded forward to accommodate taller cargo. The automatic latching system at each fold point keeps the panels securely locked in their open position at highway speeds. We recommend ensuring any exposed cargo is properly secured and that folded panels are fully latched before driving. The four-panel design gives you flexibility to cover part of your bed while transporting items like toolboxes or coolers that won't fit under the closed cover.
The MX4 is compatible with most spray-in bedliners and drop-in liners up to 1/4 inch thick. Our adjustable rail clamp system accommodates the added height of bedliners without requiring modifications. During installation, you'll position the rails on top of your bedliner and adjust the clamps to achieve a secure, weathertight fit. The cover is also compatible with most over-the-rail bed liners. Measure your specific liner thickness to confirm compatibility with the MX4 rail system.
The MX4 aluminum panels support up to 400 pounds when weight is evenly distributed across the cover surface. This capacity allows you to stand on the cover to access roof racks or load gear on top like kayaks, lumber, or cargo boxes. Always distribute weight evenly across multiple panels and avoid concentrated point loads. The reinforced aluminum construction and internal crossbar design prevent flexing under load, but exceeding the 400-pound limit or loading unevenly can damage the panels and void your warranty.
Yes, the MX4 works with most fifth-wheel and gooseneck hitch systems when the cover is folded forward. The four-panel design folds completely behind your truck cab, providing clearance for hitch installation and towing. We recommend measuring your specific hitch height and configuration to confirm clearance before purchasing. Some ultra-tall gooseneck hitches may require removing the front panel section during towing. The MX4 panels are easy to remove and reinstall without tools if needed for maximum hitch clearance.
Every MX4 kit includes four pre-assembled aluminum panels, vehicle-specific mounting rails, adjustable rail clamps, all necessary hardware, detailed installation instructions, and a registration card for warranty activation. Most truck owners complete installation in 60-90 minutes using basic hand tools — no drilling is required on most truck models. The rails clamp directly to your bed rails, and the panels drop into the rail channels. We provide step-by-step video guides for your specific truck model on our website to make installation even easier.
Clean the weatherstripping seals every few months with mild soap and water to remove dirt and debris that could prevent a tight seal. Apply a thin coat of silicone spray to the seals twice per year to keep them flexible and prevent cracking in extreme temperatures. Inspect the seals regularly for compression damage or gaps — if you notice water intrusion or visible wear, replacement seal kits are available through our parts store. Proper seal maintenance ensures the MX4 remains weathertight and protects your cargo for years.