This Defender Security 3-1/2 inch Brass Back Plate is designed to cover marred doors and allows for the conversion of a 2-3/8 inch to a 2-3/4 inch backset or vice versa.
Covers marred doors and allow conversion of 2-3/8: Covers marred doors and allow conversion of 2-3/8 inch to 2-3/4 inch backset or 2-3/4 inch to 2-3/8 inch