"7 Speed You can use only the left gear lever for 3 speeds and only the right gear lever for 7 speeds and both the left and right gear lever for 3 x 7 speeds. Suitable for mountain bike, mountain bike, touring bike, city bike, etc.Speed Control Window: The intuitive speedometer shows the driver which gear is selected while driving, making it easy to see the gear change at a glance.Trigger HandleThe Right Shifter handle is a 7-speed type trigger lever, with a lever for downshifts and a thumb button for upshifts. The left shifter is a friction/pawl thumb shifter for triple cranks.High quality materialThe bicycle shifter is made of aluminum alloy, with the best performance and maximum safety, and is equipped with a switch cable.PREMIUM MATERIAL: This thumb lever is made of durable aluminum alloy, it works great for best performance and maximum safety and long service life."