Pulse Oximeter.

Self-adjusting finger clamp and simple one-button design for easy operation. Suitable for daily use, to measure your health at any time. Can display blood oxygen SPO2 value, heart rate pulse PR value, histogram, blood perfusion index PI. The unique PI index effectively reflects the pulsating blood flow. Requires 2x AAA Batteries (not included).

Buy 3 or more items and get each for R45.