When racing your Mini 4WD, not only do you require top speed throughout the race, you also need a way to keep your car on the track at lane change and slope sections. These brakes which have a sponge sheet attached to their lower sections that slightly touch the track surface at the start of both lane change and slope sections, fractionally reduces your speed to keep you on course to victory. You can choose two height levels to allow installation for both small and large diameter tire machines. There are two kinds of sponge sheets, each with a different braking effect, allowing you to best prepare your machine for the circuit. The sponge sheets come in four parts allowing you to change the width of your brakes. Two types of hex shafts, 45mm & 72mm, are included. Can be used with any Mini 4WD PRO machines.