Aero Precision drop-in, polymer handguards for the AR15/M4 are fully mil-spec and perfect for that USGI look. They offer aluminum heat shields on both the upper and lower halves, providing heat protection for your hands. The Carbine Length handguard includes dual-layered, melonite coated head shields for increased protection. The rifle length handguard requires the use of a triangular end cap, sold separately.