20mm Tandem CNC steel bolt for Tokyo Marui AKM GBBR(Gen2) – preorder

Patented telescopic dual stage blow back system

20mm cylinder bore x 66mm nozzle travel (original 19mm x 44mm)

Full bolt carrier travel

steel CNC made bolt carrier group

SUS316L recoil spring holder

high ROF buffer spring standard

PA12GF nozzle

7075 T6 CNC made cylinder and cylinder bolb

2nd batch performs better than below video