This is a Bravo Company Vertical Foregrip known as the Vertical Forend Grip, model BCM-VG-S-BLK.
Bravo Company's BCM Gunfighter's Vertical Grip (Short) has a low-profile length for increased mobility and decreases "snag" factor. The forward angle increases the rigidity of the forearm while providing a more natural wrist angle. It can be mounted in reverse angle to increase your control when grabbing the handguard and grip. The flat sides give better yaw control to the shooter during firing and non-firing manipulations and its aggressive texture and storage volume combined with its modular design allow for improvements and adaptation in the future. It has a cross bolt design to work with improvised tools (such as a quarter) and to allow for easy adjustment or re-tightening. Reversible clamps allow the user to set up fasteners to reside on either side and spring-loaded clamps to make installation and removal easier. Manufactured from high quality" impact resistant polymers and made in the USA.
Features:
Low-profile length for increased mobility
Can be mounted in reverse angle
Aggressive texture and storage volume
Cross bolt designed