Easily removable and replaceable Spark pads Heavy-duty polymore frame with "quick click" hook and strap Proprietary 50mm urethane wheels with sealed bearings Fits shoes US youth 12 through adult 12 Includes Spark Pads and Skid pads Fire up your afterburner and get your spark on with the high-flying Jetts by Razor. Just step up, strap down and take off with these easily adjustable, always awesome heel wheels to transform your ordinary running shoes into the hottest way to roll.