Specification: Product material: ABS Product size: 6*4*3cm (Due to manual measurement, there will be an error of 1-3mm.) Note: The package does not contain batteries. Two AAA batteries are required for use. Feature: 1.Small and portable, stylish and simple, monitor blood oxygen anytime, anywhere. 2.Built-in silicone membrane, more comfortable to wear, ergonomic design, fit fingers, soft and comfortable. 3.One-key quick measurement, 8 seconds display measurement results, multiple monitoring data, multiple data display, giving you a rich monitoring experience (blood oxygen saturation, pulse rate, perfusion index). 4.Automatically detect shutdown and save power and energy, automatically detect the position of the finger, and automatically shut down after 5 seconds without a finger, saving energy and power. 5.Real-time spot-checks. Datas storing and data analysis function. Package Including: 1*finger clip pulse oximeter 1*Operation instructions