Defender Security U 9498 Backplate, 3-1/2-Inch, Antique Brass,(Pack of 2) Antique brass plated steel Use with 2-1/8in. bore lock sets Covers marred doors Allows conversion of 2-3/8in. to 2-3/4in. backset Also can convert 2-3/4in. to 2-3/8in