Unique to PowerDyne Magic Cushions is the Power Assist™ formula for total performance. Made from high quality urethane, Magic Cushions (some people call them "bushings") retain energy and release it when you need it most. Just like shocks on a car, Magic Cushions soak up the imperfections of the surface, keep you connected to the road ahead through enhanced feedback, load up when pressed to the limit, and then release your stored power in a forceful yet predictable manner. Available in 4 hardnesses, they are the most responsive cushions available for your skating skills. The PowerDyne Hop-Up Kit fits most standard roller skate trucks with the added action of conical top cushions. The kit includes 4 high rebound universal cushions, 4 high rebound conical top cushions, 4 cushion cups, and 4 conical top cushion cups. Everything you need to upgrade your plate!What they're saying: Skaters are absolutely thrilled with all forms of the Magic Cushions! "Punchy," "responsive," "tons of life," and "amazing rebound" are just some of the comments we've heard. Often times skaters will mix and match a couple different packs of Magic Cushions for true customization.Recommended plates: PowerDyne Thrust, Triton, and DynaPro. The cushions will fit PowerDyne Revenge and Rival plates but the Revenge and Rival have slightly larger diamter Kingpins than the Thrust, Triton, and DynaPro and requires different cushion cups. The Hop-Up Kit will not fit PowerDyne Reactor plates due to the length of the Reactor Kingpin.Recommended use: Check out the PowerDyne Hop-Up Kit if you're interested in gaining a larger range of motion over your standard cushions. For easy installation and removal, a small amount of lubricant or mild soap is recommended on the inner ring of the cushion that touches the Kingpin.