I paid $150 for this mag and hardly used it... Never sat around loaded. Feeds %110 guaranteed! I used it in a HK USP 40 S&W, it will hold 28rnds for 40 caliber or 31rnds 9mm. will work in both 9mm and 40s&w Full Size USP's. $95 Shipped, save $50+ Accept PayPal or MO. PP+%3 Link to Midway USA's HK USP Mag Add - $145+shipping