This Glass Door Knob is a brass constructed, single-sided model with a blind fastener end cap. Ideal for sliding doors, cabinet doors and standard frameless swinging glass doors. Knob extends one inch (25.4 millimeters) from the surface and measures 3/4 inch (19 millimeters) in diameter. End Cap protrudes only 1/8 inch (3.2 millimeters) from the glass surface. Requires a 1/2" (12 mm) hole in glass for installation.