JERRY-II Pulse Oximeter Parameters: Two Parameters:SPO2, Pulse Rate. Features: 1. Small, light, easy for carrying and handling; 2. Builtin Li_ion rechargeable battery by connecting USB power cable to PC,longtime operating time(Can operate 15 hours with fully charged battery); 3. Audio and visual alarm,sensor-off alarm, alarm limit can be set; 4. Automatic Power-off within 3 minutes; 5. Battery capacity indicator.