✔【Four-Piston Driving】4-Piston to drive friction disc on both sides at the same time, strong braking force, quick brake, timely reset. The brake pads automatically return, the braking is stable and the braking force is strong. Strong accessories provide you with a high level of security. ✔【Aluminum Alloy Material Quiet Braking】Sturdy and wear-resistant, can protect your rotors and do not make any noise when you cycling. Fast braking response, stop in time to avoid the occurrence of unsafe situations. ✔【Easy Installation】It is very easy to install by yourself. Front tube length: 800mm. Rear tube length: 1450mm. Item Weight: 575g / 1.3lb. Unboxing to install and use, installation can be completed in 5 minutes ✔【Compatible Most Bikes】The length of the front tube is 800mm, and the length of the rear tube is 1450mm. Suitable for most mountain bikes, electric ebike, scooter etc. ✔【Best Gift for Cycling Lover】Suitable for cycling enthusiasts or beginners who are just beginning to try cycling.Upgrade your old parts or try assembling your new car yourself.