The USMC version of the M16A4 features a handguard with four Picatinny rails for mounting optical sights, laser pointers, night vision, forward handgrips, removable carry handle and flashlights.

• 美国海军陆战队的M16A4护手盘上有4条皮卡汀尼导轨用来装备光学瞄准镜，激光瞄准具，夜视瞄准镜，前把手，可抽取式把手和手电。