Solid brass door knocker in a light pewter finish with a 160 degree viewer. Screws included. Provides one-way 160 degree angle door viewing. To be used on doors 2 inch thick or under. Mainly used for doors 1-3/4 inch. thick or under. The screw supplied can be cut to use on doors less than 1-3/4 inch.. For larger doors use a #8-32 machine screws, not included. Screw holes are 6-5/16 inch center to center.