Close unwanted Strain Relief mounting holes or other double faced or Double D holes punched or molded with two opposing flats. Convex, matte finish head tapers to a thin edge. Quick and easy installation. Lock firmly in panels 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.