A high quality variator kit from Italian performance parts specialists Polini, suitable for scooters fitted with the Minarelli 4-stroke 50cc engine. With the Hi-Speed, Polini offers one of the most powerful variators on the market. The roller tracks are calculated in such a way that the available engine power is translated significantly better to the road meanign increased acceleration and a slight improvement in overall top speed. Includes 6 x 4.9g rollers (16x13mm), 1 set of clutch springs and a stronger counterpressure / torque spring. Suitable for fitment on the following models: Yamaha Aerox 4T 50cc (2014-17) Yamaha Aerox 4T 50cc (2018 Onwards - Euro 4) Yamaha Giggle 4T 50cc SA351 Yamaha Neos 4T 50cc (2009-12) Yamaha Neos 4T 50cc (2013-17) Yamaha Neos 4T 50cc (2018 Onwards - Euro 4) MBK Booster X 4T 50cc MBK Nitro 4T 50cc (2014 Onwards) MBK Ovetto 4T 50cc (2009-12) MBK Ovetto 50 4T 50cc (2013 Onwards)