Kyosho ORG078 O-Ring 0.78 Black (4)

Kyosho ORG078 is a genuine four-pack of 0.78 o-rings for the big bore shock system on Kyosho's 1/10 scale off-road vehicles. These are the lower cartridge o-rings that also serve the spring pre-load collar, sealing the shock cartridge and giving the collar enough friction to hold its position under vibration. That second job matters more than it sounds: a collar that creeps changes your ride height and spring preload mid-run, which quietly ruins a setup you spent practice sessions dialing in.

O-rings are consumables that harden and take a set over time, so replacing them at rebuild intervals keeps shocks sealed and settings stable. These install as direct factory replacements in Kyosho's big bore shock sets, fitting the Ultima RT5, RB5, RB6, SC, and DB along with the Lazer ZX-5 series and later cars like the RB7 built on the same damper. Package includes four o-rings, enough to service a pair of shocks. Fit them with a light coat of shock grease.