Yamaha Banshee Mono Block Base Gasket. Fits Cheetah Mono Block, works great for Cheetah Cub and Super cub clears sleeves for 66mm -73.5mm bore sleeves. .018 thick. Excellent Template to use for case tunnel porting. Soft Crush Cushion Material outside over a metal Shim inside to make durable from blowing out or breaking.