Features: . Does not include 18650 batteries; 6x 18650 batteries required (sold separately). DC 5.5x2.1mm port supports input and output functions; compatible with DC adapter for easy use. DC 5.5x2.1mm port powers 12V devices such as LED lights or routers. USB 5V port charges smartphones, GPS devices, tablets, and other 5V devices. Suitable for bike LED lights (5V or 12V), routers, and charging mobile devices. Designed to simplify battery pack replacement; supports DIY battery installation without spot welding, reducing internal resistance and improving discharge performance and battery life. Power source: 18650 rechargeable lithium batteries. Dual output: USB and DC ports. DC output voltage is 12V (for 12V devices like bike lights); USB output voltage is 5V (for smartphones and other 5V devices), supporting versatile usage. Built-in overcharge and over-discharge protection for enhanced battery safety and longevity. Specification: Material: Plastic + metal Color: Black, Red, Blue Input Voltage: DC 12V Output Voltage: DC port 12V Overcharge protection voltage: 12V Over-discharge protection voltage: 5V Discharge protection current: 9A Standby current: Under 80mA USB Output Voltage: DC 5V +/- 0.2V USB Output Current: 1000-2100mA Dimensions: 9 x 6.5 x 5 cm Cable length: 57 cm Belt length: 53 cm 18650 batteries not included Note: Insert batteries correctly. Charge when the power indicator light flashes. Do not use the device in water. Waterproof rating: IPX4. Packing list: 1 x Waterproof 6x 18650 battery box case (without batteries) 1 x 5.5x2.1mm adapter