SBR Rubber Grommet --- Inner Diameter 9/16" --- For Panel Hole Diameter 3/4" --- Outer Diameter 1" --- Overall Thickness 5/16" --- For Panel Thickness 1/16" --- Used to Insulate and seal around holes cut in solid panels ---- Also Used to dampen vibration and minimize abrasion. ---- Durometer hardness - 55A. --- Color is black. ---- Flexible grommets made of SBR rubber ---- Temperature range –30° to +175° F. ---- 3 pack