Brand:Shimano name:EF500 Level:3x7/8 speed Attributes: mountain bike finger dial (left 3 speed right 7 /8speed) Weight:average x395grams Diameter of mouth :22.2mm Characteristics: 1. Made of aluminum alloy, the bicycle transmission is lightweight with integrated design, easy to control. 2. Visual gear display ensures gear shifting is clear at a glance. 3. Left and Right Handles: 3-speed Left Steering Wheel, 7/8/9 Speed Right Steering Wheel.3 specifications to meet your needs. 4. Installation is simple and once properly installed, it will work properly. Fully suitable for mountain bike / City RV / folding bike.