Shock Tamer hoof pads feature a dual density polyurethane which allows the pad to both absorb and dissipate concussion. The grey material is raised slightly above the black and absorbs concussion, while the harder black material dissipates it away from the hoof and the leg.  Rim Pad measurements:  5-5/8" side to side, 5-1/2" toe to toe, 1-3/8" width & 1/8" thick.