Designed for the URGI rail (Upper Receiver Group Improved), the Geissele Rail Panels feature an aggressive texture that greatly increases the ability to grip and handle your carbine and are made from a carefully selected defense grade polymer that is not only proven for its durability under hard use but also its ability to act as a heat shield. Geissele Rail Panels are available in Black and DDC. NOTE: Geissele Rail Panels are designed to work with Geissele's Super Modular Rails. Compatibility with other rails are unknown. Mfg: Geissele Automatics