An extended 20-rd magazine for the Heckler & Koch USP (Full Size) pistol in .45acp. The magazine body is constructed with heat-treated blued-steel, with a follower constructed of a proprietary DuPont Zytel based polymer to ensure a long service life. The springs are made from heat treated Chrome-silicon wire for increased reliability and smooth feeding. The magazine has an o/a length of 7.25?, and includes a molded grip-sleeve to fill the gap between the end of the grip-frame and the magazine base-plate. Made in the U.S.A.