These are the outputs joints of the differentials

a genuine Losi Racing replacement built for the Super Baja Rey

One single speed primary gear(20/30T)

Diameter of Outer Housing: 1

With its 87 tooth

HPI Racing 115544 Pro-Series Tools 7.0mm Box Wrench Trains These are the outputs jointsHPI Racing 115544 Pro Series Tools 7. 0mm Box Wrench HPI Racing Pro Series are made to exacting standards to fulfill the needs of all RC hobbyists, from bashers to pro level racers. These tools will perform and look great for years. Features: Large handle for ease of use with or without pit gloves Lightweight shaped composite handle with hanger hole Orange anodized aluminum accents Hardened steel tool tips Quick hex driver size identification Laser