Powerdyne Magic Roller Skate Cushion Hop-Up Kit fits most standard roller skate trucks with added action of conical top cushions (bushings). The cushions retain energy and release when needed like shocks in a car. 

The Powerdyne Hop-Up Kit is recommended for those interestedin gaining a larger range of motion over your standard cushions.

• Recommended Use With Powerdyne Thrust, Triton and Dynapro Plates
• Fits Revenge plates but Revenge plates come with conical cups. So you're better off just getting Revenge Magic Cushions unless needing new cushion cups.
• Hardnesses:
• Red = Soft 78A
• Orange = Medium 82A
• Yellow = Hard 85A
• Purple = Extra Hard 89A