FeaturesWorks for HeadPhone-Look CableSpeedometer and pulse tracking connector are via 3.5mm jacks on the back of the monitor - adapters (NOT INCLUDED) may be required if device also has FEMALE sockets (rare cases). Compatible with most indoor bikes - for exercise bikes with "headphone jack", see connection advice. For example, many bicycle models from Sunny, PooBoo, L-Now, Snode, Exerpeutic, Pleny, Yosuda, Ativafit, Faafuu - 95% of Amazon brands as well as national brands Heart rate monitoring function optional A function optional that works with bikes equipped with heart rate sensors (usually 2 metal parts on the handlebars). Some models may require rewiring. 2 AAA batteries not included - NecessaryBattery NOT included. SpecificationModel: ZT-JP040 counting range: 9999 (pcs) Input signal voltage: 1.5V(V) Specification: SM connector size: 147*124mm LCD screen size: 50*23mm Tips: Please allow 1-3cm measurement error. Photo color might be slightly different from the actual product due to color display of different monitors. The product includes: 1x speedometer monitor.