· Product Dimension: The 3.7V 18650 battery size is 67*18*18 mm (This is Button Top Battery, please ensure the size before purchase)· Rechargeable Times: Could be recharged more than 1000 times ( WARM TIPS: Please charge fully before first use, and charge the battery before it is completely drained)· Applicable Device: Uiversal charger for different types of 3.7V cylindrical lithium batteries. LED Flashlight , Headlamps, Doorbells, Toys, cameras, radios, RC Cars etc· Safety Assurance: Our CBJJ 3.7 volt rechargeable batteries are tested under strict quality control standards for safe and reliable use. Protect battery from over-charge, over-discharge, short-circuit and over-heat with multiple intelligent security protection settings· Store Service: Response within 7*24 hours. Please feel free to contact us if you have any questions about our item, we will provide you professional solutions and satisfactory services