Crystal Angel K-3 Generation OLED Portabel Fingertip Digital Pulse Oximeter Blood Oxygen Saturation Monitor With Luxury Dual-Color OLED Display in 4 directions and 6 modes, batteries and lanyard Measure and monitor your pulse, pulse strength and blood oxygen level (SpO2). Show the reading in numbers as well as the waveforms (plethysmograph) and bar graph to give visual indication of the irregular, weak heartbeat or incorrect reading. Luxury Dual-Color OLED 4 directions displays with Waveforms (plethysmograph) and Bar Graph to see the result from any direction easily. One button touch for setting and last display mode saved after power off. Easy and Convenient One Button Operation, Auto power-off after 5 Seconds. It comes with realtime audio alarm system. You can set upper and lower SPO2 or PR limits by yourself. Super fast, accurate measurements of SpO2 and pulse rate by digital processing. Fit Child to adult all finger sizes. Suitable for sports enthusiasts like mountain climbers, skiers, bikers or anyone interested in measuring their SpO2 and pulse rate.