Features: 1. Ergonomic design, compact and light 2. Easy- to use. 4. Accurate FHR detection, LCD display status 5. Fetal heart beat sound output via ear-phone, High fetal heart beat sound quality 6. Li-battery operated 7. Auto power off for energy saving 8. Easy to use, no mechanical moving part, high reliability 9. Long time continuous use ( more than 4 hours) Size: 130 mm X 87 mm X 30 mm