Set of 2 Super Slider POM Rear Wheels for the Razor Ground Force Drifter (Blemished) IZIP Via Mezza The boost box assembly is Q76 8339 The boost box assembly is made for lift chairs with FirstUp™ technology and can reduce the rise time by around 15 to 19 seconds If replacing "EZ" chair joystick or controller (noted by a label on the back that has DK PMA01 Shark) you will need to replace both the controller (has Invacare logo with DK PMA02 03 MK5) and the joystick (has Invacare logo with DK REMI01 MK5 CSPJ on bottom) together If all you need to replace are the wheels our Scratch & Dent set of two Super Slider POM rear wheels for the Razor Ground Force Drifter and Razor Ground Force Drifter Fury come ready to mount