Kyosho ORG045S Silicone O-Ring P4.5 Slim (15)

Kyosho ORG045S is a fifteen-pack of genuine P4.5 slim-profile silicone o-rings. These small seals are specified for the gear differentials on Kyosho's 1/10 off-road vehicles, where they seal the outdrives against the diff case so the silicone fluid inside stays put. A healthy set of o-rings keeps diff action consistent; once they wear or flatten, fluid weeps out, the diff gets loose and inconsistent, and handling suffers. Because silicone stays flexible and resists the diff fluids they live in, these seals hold up well between rebuilds.

The slim P4.5 profile is the exact size Kyosho calls for in the sealed gear diffs used on the Ultima SC and DB, and the same size services other Kyosho gear differentials that spec a P4.5 ring. They install as direct replacements during a routine diff rebuild with no modification needed. With fifteen o-rings in the pack, one purchase covers several full diff services, so you can refresh the seals every time you change diff fluid.