The Compensator V2 is described in the game as:
Reduces recoil. It is incompatible with suppressors.
You’ll find it south of central Montuyoc in an abandoned farm. The accessory case is on a unit in the farmhouse kitchen. There are only three sicarios here, spread out making them easy pickings. Approach however you like and take them down.
The Compensator V2 muzzle reduces recoil more than the regular compensator (found in Monte Puncu) which is great, and this is so easy to collect if you’re in the area anyway you may want to try it.
As always, the two downsides are it slightly reduces noise reduction, and when used, you can no longer equip the suppressor on your gun. This is where compensators really make sense is for LMGs. Unless you run with the Stoner LMG A1 (available in Pucara) which is the only LMG you can equip with a suppressor, you should definitely be using a compensator on your LMG in my opinion and the V2 is the superior option.