SpecificationModel: ZT-JP040Counting range: 9999 (pcs)Input signal voltage: 1.5V (V)Specification: SM connectorSize: 147*124mmLCD Size: 50*23mmFeatureWorks for HeadPhone-Look CablesBoth 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).Compale with Most Indoor Exercise Bikes - for Stationary Bikes with "head phone jack" look connection tips. E.g. many bike models by Sunny, PooBoo, L-Now, Snode, Exerpeutic, Pleny, Yosuda, Ativafit, Faafuu - 95% of Amazon ds as well as domestic dsOptional Heart Rate Monitoring FeatureAn optional feature that works with bikes with pulse sensors (usually 2 x metal pieces on handle bars). Re-wiring MIGHT be required for some perticular models.2 x AAA Batteries Not Included - RequiredBatteries are NOT included.Note:1.Please allow 2-3mm differences due to manual measurement.Package Include 1*Monitor Speedometer