Large Rubber Grommet For 1/4" Panel Thickness (Hard To Find Item) -- Inner Diameter 3/4" -- Outer Diameter 1 5/8" -- Overall Thickness 7/16" --- For Panel Thickness 1/4" -- For Panel Hole Diameter 1 1/4" -- Used to Insulate and seal around holes cut in solid panels -- Also Used to dampen vibration and minimize abrasion. -- Durometer hardness 50A. For Indoor Use Only -- Color is black.-- Flexible grommets made of Buna-N rubber -- Temperature range 0° to +250° F.