FAB Defense has a Tactical Folding Foregrip that lets you chose between vertical and folded for flexibility depending on what style you need. It is made of a high strength polymer to take the bumps and grinds of use and still last.
Specifications and Features:
FAB Defense Tactical Folding Foregrip FGG-S
Specifically designed not to interfere with firing when in horizontal position
Quickly transforms from a horizontal grip to a vertical grip
Easy and fast adapt/removal mechanism
1913 MIL-STD picatinny rails