Z-Parts Metal VFC M4 PFAS Complete Bolt Set

Z-Parts Metal VFC M4 PFAS Complete Bolt Set Steel Bolt With Aluminum Nozzle Features an FPAS for tuning FPS levels for your Gas Rifle This unit also features a tool for precise adjustments Suitable For M4 & Umarex (Elite Force) HK416 Series Gas Blow Back GBB Airsoft Rifles (by VFC)