The 66L Rigid Mount is a hard-mounted system designed to be able to mount a 66L Rugged Case to your roof rack or anything with mounting capability. Its design allows the mount to shoehorn into the tie-down channels of the 66L Rugged Case and has 1/4" holes to bolt down to your rack or flat surface. The mounts are .188 black powder-coated steel. *Mounting hardware not included*