Steel, matte black finish. 3-Pin fits all guns with separate trigger, locking block, and trigger housing pins, including early 2-Pin G19. Does not fit early G17, 17L, and 34 2-Pin guns. 2-Pin fits G17, 17L, and 34 that do not have a locking block pin, manufactured from 1986 to mid-2002. 37/38/39 fits all G37, 38, 39 pistols including 22 Gen 4.