Description: Features: 100% brand new and high quality. 18650 or 26650 Battery is not included, Only Power Bank Case. 1. Specical and Only for 2x 18650 or 26650 Li-ion rechargerable battery , please install same battery capacity for usage 2. 8.4V DC input and output, 5V for USB output to charge mobile phone faster 3.DC 5.5x2.1mm interface has 8.4V charge input and output functions. 4.USB port is only for output, support connect to mobile phones or other digital products 5.Customers can choose their own battery, capacity from your custom, convenient customer to experience, large capacity to provide long time endurance capability 6.Overcharge protection and short circuit protection. 7.Don't use the device in the water. Waterproof standard is IPX7 8.With ON OFF switch,easy to use. 9.If you use 18650 battery, you need to insert the battery converter. Specifications: Material:Plastic+metal Color:Black Size: 9.5x7.3x2.5cm Cable length: 36cm Input: DC 8.4V Output 1: 8.4V (DC) Output 2: DC 5V-Max 2100mA 18650/26650 Batteries are not Included. Package includes: 1 X Waterproof 2x 18650/26650 battery box case.(without battery ) 2 X 18650 to 26650 battery converter