Mouse Fart upgrade O-ring

-Improved rubber composition

-Further improves FPS and J stability

-Fits all series of Mouse Fart O-ring piston heads from 1.0 to 1.4 series

-High cemical resistance

-Suggested lubricant is WD40 brand dry PTFE

-Comes as standard on Mouse Fart piston head from 2022.06.10.