Features: -The RD-M310 rear derailleur is designed specifically for 7/8-speed bikes, ensuring a smooth and efficient riding experience. -The lightweight design reduces the weight of the bike and improves speed and handling. -The rear derailleur has a maximum gear count of 34T and a total gear count of 43T, making it highly adaptable and suitable for various terrains. -Mounts directly to the rear of your bicycle, eliminating the need for a frame mount. -Compatible with a variety of bicycle types, including mountain bikes, road bikes, racing bikes, city bikes, folding bikes, etc., it is an ideal choice for all types of cyclists. Specifications: .