All the foregrips in the game are described the same, as:
Aids in the manipulation of the firearm.
You can find the V2 in western Pucara province on the western edge of a lake. A Food Drop mission is nearby to steal a helicopter. The weapons case is on one of the piers.
There’s a path to the waterside from the south-west, but the approach to this is more straightforward if you use the elevated approach from the main road to the west.
There are ten bad guys here in total, including the sniper in the tower to the south. I used a combination of sync shots and sniping to take almost everybody out from a distance, then moved in closer to mop up the handful that are left who will take cover. If the enemy call in reinforcements, they’ll arrive via the main road to the west that you approached from and will leave their vehicles there, giving you time to either take them out (try using motar fire) or get the job done and leave.
The foregrip attachments (from the ‘Vertical Foregrip’ to the ‘Foregrip V4’) all provide the same benefit and trade-off, just to varying degrees. Each improves handling while sacrificing a little accuracy.
The V2 is an improvement on the basic Vertical Foregrip found in Itacua and which one you choose will depend on the balance you strive for with your gun stats. For more foregrip accessories, check out the V3 found in La Cruz, or go for the V4 which you can pick up in Monte Puncu.
Personally, I like to rock a foregrip on an LMG or shotgun for the added mobility.