Inner Diameter 1" Outer Diameter 1 3/4" Overall Thickness 1/2" For Panel Thickness 1/8" For Panel Hole Diameter 1 3/8" Used to Insulate and seal around holes cut in solid panels Also Used to dampen vibration and minimize abrasion. Durometer hardness - 55A. For Indoor Use Color is black. Flexible grommets made of SBR rubber Temperature range –56° to +200° F