Molded of transparent polycarbonate for internal viewing or light transmission. Snap into mounting holes with fingertip pressure-no tools required. Multiple sizes for use in .187" (4,7 mm) to 2.000" (50,8 mm) diameter holes. Lock firmly into panel up to .125" (3,2 mm) thick. Locking fingers in fractional increments up to the maximum panel thickness. Approximate Head Thickness: .062" (1,6 mm). Thickness may vary. Available in a variety of tints–consult Heyco.