This is a pair of Heavy Duty Traxxas rear Drag racing shocks for the Jato, Rustler and Bandit. These are a great length for either stock or short arms conversions.
These shocks are stiffer than stock and have more dampening to reduce squat and keep car planted on launch.
 
Choose either:
20 lb or 18.3 lb spring rate. Both work great so its just personal preference