UMP pistol arm brace, designed to fit the US made TMP receiver and any other pistol's that use the UMP style hinge. This arm brace is designed to fold and latch on the TMP platform and clears the ejection port. The length of pull is under the ATF suggested maximum length of 13.5 in. If you use this on a different platform, keep in mind the length of pull needs to be under 13.5 in. This is a single flap, hard polymer design with an adjustable strap for left and right handed users. Do not use this product on the USC rifle. All USC's are rifles. There is no pistol option. Braces are still subject to ATF interpretation per platform, while these are specifically designed as a single flap style pistol arm brace incorporating the patented SB Tactical forearm velcro strap, we offer no legal advice or approval letters for this product.