Rubber Hole Plug for 1 3/8" Opening 1 3/8" Diameter Rubber Grommet Without a Hole Hard To Find Item Has 1/16" groove around outer circumference For Installation in 1/16" Thick Panel Can be used to seal hole in panel or create your own hole in center for custom application For Panel Hole Diameter 1 3/8" Outer Diameter 1 3/4" Overall Thickness 7/16" For Panel Thickness 1/16" Durometer hardness - 55A. Can be used indoors or outdoors. Color is black. Temperature range –56° to +200° F