?????Double disc brake?Quality disc brake,easy to set and adjust, simple to operate, the brake with handle shape is suitable for 2-finger or 3-finger operation. Provide protection for your safety. ?????With good toughness, elasticity and impact resistance?The spokes with high elasticity and high toughness are connected to the hub along the tangential direction, the external impact force is buffered and dispersed by the spokes, making the hub receive instant impact Weaken. ?????Great ride experience?21-speed bike with Shimano rear derailleur delivers consistent response for uphill and downhill rides. ?????Reminder? The higher the gear, the more difficult it is to pedal, and the faster the speed. On the contrary, the lower the gear, the easier it is to pedal, and the slower the speed. You can adjust the gear according to your needs. ?????After-sales service?If you have any questions, please feel free to email us, and we will reply to you within 24 hours.