This is a Samson Manufacturing Corp. Vertical Foregrip known as the Vertical Forend Grip, model ML-VG-02M.
Samson's M-LOK Vertical Grips are made of solid aluminum with a steel rod for maximum strength. The M-LOK adapter plate is designed to M-LOK spec and will mount to all M-LOK attachment points. The two-piece design allows you to remove the grip from the rifle while leaving the lug in place. This is the 4" medium grip that fits the AR-15.
Features:
Samson M-LOK 4 Medium Vertical Grip;Fits AR-15