We have done all the hard work and spent a lot of money in research for you and these parts that I am now selling are the best and will be the right type of upgrade that will give you the best benefits. These parts are limited so first in first served.
Replace the faulty standard oring and see the amazing difference.
Increase distance/power output due to better seal
YOU ARE BUYING BEAST UPGRADE:
# 1 x Green Oversized O'ring to suit M4A1 GEN8