Crane Hi Clearance AMC 20 diff cover. Features: smooth lipless design to prevent hanging up on rocks. Recessed design helps prevent damaged to bolt heads. Bolts are grade 8, 12 point counterbore style to allow correct torque and look good too, and are included with every cover. Hi Grade RTV sealant is included also upon request. Sealing surface is machined flat to insure no leaks. CHC AMC20 covers are cast from Hi Strength 8620 Chromoly Steel. All Crane products carry a lifetime free replacement warranty against breakage. Designed for extreme off road abuse.