High Quality Rubber Flush Plug -- Fits 1 3/4" opening in 1/16" thick panel -- SBR Rubber - Can be used to seal hole in panel or create your own hole in center for custom application For Panel Hole Diameter 1 3/4" --- 1/16" groove around outer circumference --- Outer Diameter 2 1/8" --- 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. ---