Finger is an economical and accurate method to detect pulse rate and blood oxygen saturation by finger. Small size, easy to carry. Suitable for daily use, measuring at any time. Resources: Multi-function: Digital can be used to accurately measure pulse rate and blood oxygen saturation levels. Easy to Read: Supports SPO2, pulse and bar graph, you can see the result very clearly with the LED screen. Easy to Use: Precise and reliable one-button operation, just clip it to your finger and turn it on at the of a button. Auto power off after 5s when not in use. Widely Applicable: Suitable for daily use. Widely used in family, oxygen bar, sports physical care, etc. Compact Size: The oximeter is and portable. Specifications: Blood oxygen measurement accuracy: 70 ~ 100%, ± 2%, less than 70% undefined Blood oxygen measurement range: 0 ~ 100% (resolution is 1%) Pulse measurement range: 30~250BPM (resolution is 1BPM) Auto power off: when no finger is inserted, it automatically power off in 5 seconds Battery: 2 AAA batteries Package Size: 85x65x40mm/3.3x2.6x1.6inches Material:PVC colour:Blue White Package Contents: 3 x Oximeter 3 x lanyard 3 x Chinese and English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.