Compound hinge system and field replaceable latches that allows the lid to swing out and completely around to lie flat against the main body of the case, or you can go lid-less with an effortless lift motion and reinstalled with the same ease in seconds. The front and rear lids are designed to protrude into the base of the case approximately 1" and their unique double wall structure makes them incredibly stiff where this intersection occurs. Making this new generation of shock racks mil-spec sealing characteristics with significantly fewer latches than most competition. This allows for rapid deployment in an up-right configuration -- even when stacked. The standard depth front to rear rail is 24" and each lid is 4" deep. The 24" SKB shock-rack system stacks securely with the wheels on or off and this revolutionary design is also the only shock rack that will open front and back while stacked. The inner rack chassis is built of high strength / lightweight aluminum alloy and 11 gauge hot rolled carbon steel rack rails to DIA-310 standards. Shock and vibration mitigation is accomplished with eitht (8) elastomeric isolators rated for a payload range of 40 lbs. to 150 lbs. in a standard configuration and up to 300 pounds in a special order extended payload configuration allowing adequate sway space for ambient air circulation and heat dissipation. The rack rails come pre threaded for standard 10-32 hardware and mounting screws are included.