This is a factory original large backstrap grip insert for Smith & Wesson M&P full-size pistols. It's compatible with M&P 1.0 models in 9mm, .357 Sig, and .40 S&W calibers. The backstrap system lets you customize the grip size to fit your hand perfectly - this large size is great if you have bigger hands or prefer a fuller grip. Installation is simple and doesn't require any tools - just swap out your current backstrap for this one. Made from durable polymer with the same quality as the original equipment. Having the right grip size improves control, comfort, and accuracy when shooting. If your M&P came with multiple backstraps and you've lost the large one, or if you just want to try a different grip size, this factory original part ensures perfect fit and function. The black color matches the standard M&P finish. Whether you're looking to improve your shooting ergonomics or just need a replacement part, this backstrap delivers the quality and compatibility you expect from genuine Smith & Wesson components.