Feature:1. Compatible with both shifting and braking function, easy operation.2. 3 speed left brake lever, 7 speed right brake lever, totally 21 speed for optional.3. Made from aluminum alloy + plastic, hard and thick, resistant to collision and not easily deformed.4. Wide transparent dial allow you to read the speed more direct and clear.5. Ergonomic knob and energy saving pulling bar make shifting gear easier and quicker.6. Simple to install and suit different types of bicycles.Specification:This is a kind of fine quality bike shifter, made from aluminum alloy, durable. 3 speed left brake lever, 7 speed right brake lever, precise gear changes. Wide transparent dial makes it easy to see which speeds you're in. Features:Compatible with both shifting and braking function, easy operation.3 speed left brake lever, 7 speed right brake lever, totally 21 speed for optional.Made from aluminum alloy + plastic, hard and thick, resistant to collision and not easily deformed.Wide transparent dial allow you to read the speed more direct and clear.Ergonomic knob and energy saving pulling bar make shifting gear easier and quicker.Simple to install and suit different types of bicycles.Specifications:Material: Aluminum Alloy + Plastic.Color: Black.Type: Type 1 / Type 2 ( optional ).Product Size: 16.5 * 8 cm / 6.5 * 3.1 inUnit Weight: 172 g / 6.1 ozPacking Size: 24 * 17.2 cm / 9.4 * 6.8 inPacking Weight:365 g / 12.9 ozPackage List: 1* Pair of Bike Brake LeversPackage List:1* Pair of Bike Brake Levers