Products Package Includes: 1 × 1Pcs UltraFire 18650 4000mAh 3.6 – 4.2V Lithium Batteries without Board Black. This is 1pcs 18650 4000mAh 3.6-4.2V Rechargeable Lithium Battery Black. There is no doubt that they are high quality and durable as well as high energy density. Also, these batteries are regarded better both in low and high temperature operations. Generally, they fit for camera, watch, calculators and other electronic devices, and provide excellent continuous power sources to your device.High quality and durable. Provides excellent continuous power sources to your device. High energy density, long life battery. It is good both in low and high temperature perations. Fit for camera, watch, calcutors and other electronic devices.