Fits 1/8" to 1/2" Thick Glass Fits holes from 3/16" to 1" diameter Shower Door Chrome Back-to-Back Knob Handle measures 1-5/8 inch outside diameter, and extends 1-9/16 inches from the door surface. Fits holes from 3/16" to 1" diameter. Material: Plastic Finish: Polished Chrome Glass Thickness Range: 1/8" to 1/2"