Hera USA HFG Vertical Front Grip, Fits AR-15, Internal Compartment, OD Green 11.09.03 Hera USA's HFG Vertical Foregrip is a fantastic upgrade for your AR-15 rifle. The HFG Forward Grip mounts under your barrel on a standard picatinny rail platform. It's a lightweight versatile improvement that features an internal compartment for small items or battery storage. Turn your AR platform firearm into a highly effective weapon with the HFG Vertical Foregrip.