Comimg soon to the GHK AK Gas Blowback Series is the Hephaestus CNC Steel Bolt and they released a pre-release demonstration with Green Gas at Room Temperature 19°C... "No Compromise on Performance. Precise weight-balancing for strong and sharp "kick" with decent rate of fire and consistent output. The Hephaestus CNC Steel Bolt Carrier Series for GHK AK GBB System - Available Soon..."