Fetal Doppler fetal heart monitor patented product of choice for medical products Chenhao medical TX288 fetal favorite technical indicators? Large screen display, blue backlight display instantaneous and average fetal heart rate FHR fetal favorite? High-quality high-power output , your voice loud, clear fetal favorite? wide beam, high sensitivity, the use of technology to filter out noise favorite child? whispered acoustic output power, rest assured fetal heart monitor fetal favorite? Fetal Doppler fetal heart rate exceeded the warning? charging indicator, full instructions, less power indication favorite child? using DSP technology, more advanced, more accurate fetal favorite? optional rechargeable battery or # 5 AA batteries favorite child? automatically shut down, turn off automatically after a background noise does not care tire ? favorite optional probes of different frequencies Chenhao medical TX288 technical indicators l ultrasound operating frequency fw: Optional frequency of 2.0MHz and 3.0MHz, the operating frequency and standard deviation for each frequency is less than ± 10% l Ultrasonic output intensity: <10mW / cm2 l fetal heart rate measurement and display range: 65 times / min-210 times / min l fetal heart rate measurement accuracy: error does not exceed ± 2 times / min l Power: 14.4V NiMH rechargeable AA batteries Day Ten batteries (optional) l Continuous working time: ≥3 hours rechargeable battery batteries ≥1 hour l Operating temperature: 5 ℃ -40 ℃ l Relative Humidity: 30% -80% l atm: 70kPa-106kPa [favorite child, fetus monitors, baby monitors, adult multi-parameter monitor, postpartum rehabilitation instrument professional manufacturer]