Description: Ergonomic trigger speed shifter expands the display view of gear, so you can check and speed quickly. This thumb shifter works perfectly for best performance and maximum security. Made of durable aluminum alloy material, this thumb shifter is durable to use. The suitable handlebar diameter is 21mm-23mm. This thumb gear shifter is universally fit for mountain bike, city bike, road bike, folding bike, etc. Item Name: Thumb Shifter Material:Plastic,Aluminum Alloy Size Details: Suitable Handlebar Diameter: 21mm-23mm/0.83"-0.91" (Approx.) Notes: 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 Thumb Shifter Ergonomic trigger speed shifter expands the display view of gear, so you can check and speed quickly. This thumb shifter works perfectly for best performance and maximum security. Made of durable aluminum alloy material, this thumb shifter is durable to use. The suitable handlebar diameter is 21mm-23mm. This thumb gear shifter is universally fit for mountain bike, city bike, road bike, folding bike, etc.