Function of magnetic control car instrument, spinning bike instrument: 1. TIME: Press the MODE button to display the time. This value represents the duration of the workout. 2. SPEED: Press the MODE button to display the speed. This value represents the current speed of the movement. 3. DISTANCE: Press the MODE button to display the distance. This value represents the total distance traveled during the workout. 4. CALORIE: Press the MODE button to display the calories. This value represents the energy burned during the workout. Compatible with devices that have headphone-style cables. Both speedometer and pulse tracking connections are through 3.5 mm female jacks on the back of the monitor. Adapters may be needed if the device has female jacks (in rare cases). Compatible with most indoor exercise bikes, including stationary bikes with headphone-style connection tips. Fits many models from brands such as Sunny, L-Now, Pleny, Faafuu, and others. Suitable for 95% of home and commercial fitness bikes. Heart rate monitoring feature works with bikes equipped with pulse sensors, typically two metal contact points on the handlebars. Rewiring may be required for certain models. Requires 2 x AAA batteries (not included). Product dimensions: 108 x 163 mm LCD size: 48 x 23 mm Color: White Material: Plastic Package Contents: 1 x Monitor Speedometer with Heart Rate Function Only the items listed above are included; other products are not included. Note: Lighting and different screen displays may cause slight color variations between the image and the actual item. Measurement error allowance is +/- 1-3 cm.