Molded from a nylon material which, in the event of a fire, will not burn and will not produce toxic gases. Also formulated for sunlight resistance. Other Heyco products are available in this material-please consult Heyco. Close unneeded panel holes. Quick and easy installation. Convex, matte finish head tapers to a thin edge (Except HFP-187 glossy finish). 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. Multiple sizes for use in .187" (4,7 mm) to 2.000" (50,8 mm) diameter holes. Consult Heyco for larger sizes.