Strike Industries GRIDLOK-416-FD-9 GridLok Full Duty With Quick Detach System 9"L 1.57"D M-LOK Black Aluminum for HK 416, HK MR556, M27 IARSpecifically designed for Law Enforcement and Special Operations communities who have adopted the HK416 M27 IAR platform in the U. S. and all around the world. The Strike Industries GRIDLOK Rail for 416 gives you a primary, a secondary or multiple setup options as a quick and direct handguard swap. The GRIDLOK Rail for 416 has the SI patent pending Quick Rail Detach GRIDLOK locking latch and mounts on using the factory HK OEM barrel nut, in seconds