PolarStar Airsoft JACK™ HPA Engine Complete O-Ring Set (Excluding SMG-7)

This is a full O-ring replacement set for all versions of the PolarStar Airsoft JACK™ HPA Engine Conversion Kit, excluding the variant specifically for SMG-7 platforms (MP7 styled replicas). If you want to make sure all the seals are up to par, this is a great way to refresh them on the cheap. It's also a great bit of kit to keep in your toolbox just in case of an emergency or you accidentally lose an o-ring during installation or maintenance.