Cyma CM035 AKS-74U version 3 gearbox with stock motor Attempted to put in an ASG m105 spring, and it did not work when I tested it out. Either teeth are stripped inside, or the piston is misaligned, I have not opened it since. The replacement spring is still inside Will ship with stock spring upon request Shipping via UPS ground Willing to trade or local pickup if you are nearby to the central maryland region. Looking for repro AK zenitco furniture, AK romanian folding wire sock, or mp5 MIDCAP mags.