Built-in Lithium Battery, Rechargeable More than 800 Measurement Times Can be used for 8 house after charging for 1-2 hours Package list - 1 x Fingertip Oximeter (Built-in lithium battery) - 1 x Lanyard - 1 x USB micro cable - 1 x English user manual - 1 x Retaile Box Features: 1. Fast measurement, 3-5 seconds get readings. 2. Product adopts LED display. 3. Low-power consumption, continuously work for more than 8 hours after full charge.