The ProWin O-ring for the TM G series model 17 & 18, Hi-Capa series, and M4 MWS magazines is designed to take the prolonged pressures of green gas.
Compatibility:
Tokyo Marui G Series Model 17
Tokyo Marui G Series Model 18
Tokyo Marui Hi-Capa Series
Tokyo Marui M4 MWS GBBR
Includes:
x3 ProWin 5.5 X 1MM O -Ring for Prowin Model 17 & 18 / Hi-Capa / MWS M4A1 GBB Gas Magazine
Disclaimer: All aftermarket upgrade parts require necessary skill or modification to install and assemble, please consult with your airsoft technician if needed.