A SOPMOD stock is an upgrade to the standard M4 carbine buttstock. It is a modular stock that is designed to improve the weapon's accuracy, ergonomics, and adaptability. It consists of two parts: a buttstock that can be adjusted for length and cheek weld height, and a modular rail system that can be used to mount various accessories. The SOPMOD stock also features a rubberized buttpad for added stability and comfort. It is commonly used by military and law enforcement personnel around the world, as it enables them to quickly and easily switch between various accessories such as different sights and lasers. Additionally, the SOPMOD stock can be configured with a wide range of other accessories including pistol grips, adjustable cheek pieces, and folding stocks. By using a SOPMOD stock, users are able to customize their weapon to fit their individual needs, making it an invaluable tool for any shooter.