Automatic Identification Function: Automatically identifies lithium battery, water battery, and dry battery without distinction; handlebar diameter is 2.3 cm / 0.9 in. Wide Compatibility: Compatible with various electric vehicles, suitable for general 12V99V systems. Wiring Method: Red wire connects to shifter positive 5V, black wire to negative. Always verify controller wiring functions before connectiondo not rely solely on wire color to avoid damage to controller or handle. Material: Constructed from high-quality plastic for strength and durability, extending product lifespan. Ergonomic Design: Features an ergonomic grip design for slip resistance and comfortable handling, allowing easy speed adjustment during use. Item Type: Electric Bicycle Throttle Grip Kit Weight: Approx. 113g / 4.0oz Product Material: Plastic Efficiency: 98% Hall Grade: Linear Hall Handlebar Diameter: Approx. 2.3cm / 0.9in Package Includes: 1 x Thumb Throttle, 2 x Keys