Come and see our amazing products. Accurate and Reliable: Using the most advanced MCU chip and sensor, blood oxygen signal is collected by photoelectric sensing principle, Only need 5-8s to get your blood oxygen saturation levels, pulse rate and pulse intensity. For sports and aviation and normal use, accommodates wide range of finger sizes (8-25.44mm), children to adult. Lightweight and Portable: This fingertip pulse meter is very light and easy to carry, which is convenient to measure your oxygen saturation anywhere. It's works with 2 pcs of AAA battery. Welcome to order. Pls confirm further with us if any query about packing info, inventory status and time schedule.