This is a CMMG Rail known as the KeyMod, model 55DA299.
The CMMG AR-15 KeyMod 5 Slot Accessory Rail attaches to any standard keymod rail to mount non-keymod accessories. Made with 6061 T6 aluminum with a hard anodized black finish.
Features:
Attaches to any standard keymod rail to mount non-keymod accessories
5 Slots
