Give your wheelie model a boost with this Hop-Up Option set! It includes E-ring secured stainless steel shafts for use in lower suspension arms, giving smoother and truer movement than the original screw pins. The aluminum support bridge acts as a brace where the suspension shafts attach the lower arms to the chassis. 3x37mm Stainless Steel Shafts x2 3x52mm Stainless Steel Shafts x2 Aluminum Support Bridge x1 E-Rings x10 Compatible with GF-01 and WR-02 chassis cars.