These Pin Sets help to eliminate wear on the pivoting surfaces which helps maintain a crisper trigger pull. The TiN coated pins will give you the smoothest hammer and sear rotation possible, while eliminating pin wear. Requires installation by a qualified gunsmith. Oversize Pin Set may require reaming of some part of the pivot holes. Notes:Hammer Pin: .157" diameterSear Pin: .110" diameterFactory specification on hammer pin diameter: .157" -.002"Factory specification on sear pin diameter: .110" -.002"