Welcome to the "ZTTO Official Store"! Type: Bike Shifter Material: Aluminium Alloy Mount: Left(3 Speed)/Right(7 Speed) Features: Easy Installation, Durable, Bike Accessories Suitable Handlebars Diameter: 21mm - 23mm/0.83" - 0.91" (Approx.) Specifications: 21-speed transmission, ergonomic design of position and trigger handle. Make wider gear display vision, just take a glance at speed changes. It works perfectly for optimum performance and maximum safety. Notes: We are specialized in selling bicycle accessories, if you have a need, remember to pay attention to us! Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Left Shifter 1 x Right Shifter 2 x Brake Lines