H&K MR556 A4 and HK416 A5 Gas Vent Screws
German gas vent screw for MR556 A4 gas block.
Specifications:
- Factory reference: 1.3mm is the common factory vent screw size for MR556 A4
- Sizing reminder: Larger mm equals more venting, Smaller mm equals less venting
Compatible With:
- MR556 A4
- HK416 A5
