Intelligent virtual shifting control, seamlessly integrated with the for app, enhances your indoor training experience. Smoother, faster shifting: Enjoy seamless shifting without mechanical adjustment, eliminating chain wear and achieving faster, smoother shifting. Enhanced component compatibility: Simply fasten the bicycle chain to the cycling trainer cassette for smooth shifting without mechanical interference. Reduce power loss during training: The virtual shifting function maintains low power loss settings for the large chainring and the intermediate sprocket, reducing chain wear and extending the life of the equipment. Color: Black Material: plastic Package Contents: 1 x BC2 Cycling BLE Controller Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.