Function description of magnetic control car instrument, spinning bike instrument:1. TIME: Press the MODE button to display the time. This value represents the time from the of the movement to .2. SPEED: Press the MODE key to display the speed. This value represents the speed of the current movement.3. DISTANCE: Press the MODE key to display the distance. This value represents the distance from the to of the movement.4. CALORIE: Press the MODE button to display the calories. This value represents the energy burned from the to .Works compatible with HeadPhone-Look Cables]Both speedometer & pulse trakcing connection are through 3.5 mm female jacks on the back the monitor - adapters (NOT INCLUDED) might be needed if the device also happen to have FEMALE jacks (rare cases).[Compatible with Most Indoor Exercise Bikes] - compatible with Stationary Bikes with "head phone " look connection tips. E.g. many bike models by Sunny, , L-Now, , , Pleny, , , Faafuu - 95% of Amazon as as domestic [Heart Rate Monitoring Feature]that works with bikes with pulse sensors (usually 2 x metal pieces on handle ). Re-wiring MIGHT be required compatible with some perticular models.[2 x AAA Batteries Not Included - Required]Batteries are NOT included.Product size: 108x163mmLCD size: 48x23mmColour: whiteMaterial: plasticPackage Contents:1 * Monitor Speedometer W/ Heart RateOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.