The Trinity Angled Foregrip (this link is to the black one, the also come in dark earth color and dark ranger green) is a grip that mounts to any picatinny style rail. Until now, the only option was the vertical handle grip. The angled grip has been found to create a steadier aim when holding. Each of these angled grips come with an optional plate that will insert a finger ridge, should you desire it. Note that if you have an Alpha Black (or any m16 style shroud) you will need to add the Alpha Black Rail to mount the grip.