Handbook volume: AR310587+AR310452+AR310451This item includes :CVD-2PCSScrew Shaft 5x5 -2PCSProduct major function & usage:Lead the tires & tires to make smoothly1. Produced by harden steel #45, stronger and great durability to complete smooth driving performance.2. Better dogbone with diameter increased from 5mm to 6mm.Same as originalLength of dogbone : 85mm