Features: MKS-SP02 is a simple to operate and powerful transmission pulse oxygen module. Using 32-bit ARMCortex-M0 as main control chip, low-power, high-efficiency chip. Up to 48MHz main frequency, with very stable computing and processing capabilities. Simultaneously measuring blood oxygen saturation and pulse frequency not only displays digital results, but also monitors the continuous waveform of pulse in real-time. This module supports a finger clip shells, which is convenient to carry and easy to operate. High precised sensors, fast response, wide compatibility, suitable for mass production of finger clip pulse oximeters as main control board. Specifications: Material: Printed Circuit Board Size: Approx. 51x27mm/2.0x1.06inch Display method: OLED Communication method: Bluetooth-compatible communication Blood oxygen measurement ranges: 60-100%, resolution 1% Blood oxygen measurement accuracy: 2%, less than 70%undefine Pulse measurement ranges: 30-250bpm, resolution 1. Pulse measurement accuracy: take the biggest value of lbpm% or Ibpm. Measurement ranges of perfusion index: 0.5x20%, resolution20%. Power requirements: Two AAA 1.5V alkaline batteries, capable of providing long-term continuous measurement, easy replacement, and low power consumption Note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution. Package includes: 1x MKS SPO2 Blood Oxygen Saturation Heart Rate Acquisition Module