A. It is of good quality. B. [Many fitness spin bikes use this display] - Suitable for spin bikes with a connection prompt in the appearance of "headphones". For example, it is applicable to bikes of brands such as Sunny, L - Now, Pleny, Faafuu, etc. Around 90% of home - use bikes are applicable. C. The connections for the speedometer and pulse tracking are both achieved through the 3.5 - millimeter female jack on the back of the display. If the device also has a female jack (which is not common), an adapter may be needed (not included in the accessories). D. [Optional heart rate monitoring function] This is an optional function, suitable for bikes equipped with a pulse sensor (usually two metal pieces on the handlebars). Some specific models may need re - wiring. E. It includes 2 AAA batteries. F. Color: Black. G. Material: Plastic. H. Package contents: 1 fitness bike computer. I. Only the above - mentioned package contents are included, and other products are not included. J. Note: Light reflection and different displays may cause the color of the item to vary slightly from the actual object. The allowable measurement error is about ±1 - 3 cm.