Spear Arms CNC Steel Barrel Nut Adapter for Marui M4A1 GBB Rifle Category_Bushing One-piece CNC Aluminum Milled Upper

One-piece CNC Aluminum Milled Upper Receiver with authentic laser engraved marking

HFC22 Gas Power (Muzzle Velocity) 290 FPS (Green Gas Test @ 25C Room Temperature)

"See-Through" design allow use of Iron sight even with mount installed

-Two Ball Bearing Bushing Inside

30mm low-profile ring mount

Spear Arms CNC Steel Barrel Nut Adapter for Marui M4A1 GBB Rifle Category_Bushing One-piece CNC Aluminum Milled UpperWeight: 10g Color: Black Material: Steel Steel Barrel Nut Adapter For Tokyo Marui M4A1 MWS GBB Secure the solid installation if the barrel nut & outer barrel Include washer set to ensure a perfect fit between barrel nut & upper receiver