LCT Airsoft CNC Advanced Stainless Ribbed Airsoft AEG Cylinder (Model: Type 2)

"Great air seal, the port on the Type 2 is perfect for a DSG, it’s just far enough back where it doesn’t let out any air. Very tight fit with my stock King Arms cylinder head and seals well with any piston head I’ve thrown at it (except Retro Arms, they suck at making piston heads).

"excellent air seal, only thing is the ribs on the outside can interfere with bolt catch if your m4 has it, other than that great piston

"I don't think this is SST, maybe chrome plated brass. You'll find out eventually. Unfortunately I was NOT able to use it in my G&G build, for some reason these cylinders can't get air in them. So I used my stock G&G cylinder with the other upgrade parts and it all showed up.

Check your gearbox, if it's all closed up there's no way for enough air to enter from the back of the cylinder.
I might try to drill a hole closer to the back and see if that works on the next upgrade.

"Very good air seal, because it is ribbed it does sometimes rub against the bolt when locked back on my m4. Other than that good cylinder