Feature: 1. Display parameter : Oxygen saturation (SpO2)-- Measuring range: 70-99% measurement accuracy : 70%-90% 2%. If the value below 94%, Insufficient oxygen supply. (PR)BPM -- Measuring range: 30 bpm - 240 bpm . PI -- Measuring range: 0.2%-30% , PI means Perfusion Index , it shows Blood perfusion ability . Respiratory frequency detection(RR) -- Normal adult breathe 16-20 times per Minute. Respiratory pulse ratio is 1:4, every one breath , four Pulse beats . Normal child breathe fast than adult , breathe 20-30 times per Minute, Newborn could breathe 44 times per Minute. 2. Display Screen: Blue and Yellow two colors OLED Screen. 3. Display Directions: Four Directions, Six display modes 4. Energy saving: Two AAA batteries could use more than 40 hours 5. Voltage warning: There has Low voltage warning. 6. Automatic shut-down: Automatic shut-down in 8 secends when there has no signal. 7. Advantage: Integrating blood oxygen probe and processing display module, the product is easy to use, low power consumption, small size, light weight, and portable. Notice: 1. Please double check the direction of the battery. The 2 batteries are in different direction, please make the +/- right. 2. The finger should be plugged deep enough, or it can not take the measure 3. Please do not tremble the finger or move the body during the measurement, or the data maybe unsteady. Package content: 1. 1 x oximeter 2. 1 x cord 3. 1 x beautiful box 4. 1 x english menual For transportation reason , batteries is not included .