Features: Step up PCB: use 18650 battery to increase the voltage to 5V. Charging board: 5V 1A or 2A input for charging 18650 battery.Battery protection board: overcharge protection, over-discharge protection, over-current protection, over-temperature protection, output short circuit protection. UPS (UPS system): if input 5V, it will charge the battery and will not use the battery; If power failure, it will automatically use the battery power. Lithium battery booster module only, other accessories shown in the picture are not included! Specification: Voltage: 5V, 6V, 9V, 12V Material: Plastic & Metal Dimensions: 7.7 x 2.1 x 2.3cm/3.03 x 0.83 x 0.91inch Color: Green & Black Quantity: 1 PcNote: 1. Please allow 0-1cm error due to manual measurement. Pls make sure you do not mind before bidding.2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!3. Please use for lt;= 5W device. Package Included:1 x Lithium Battery Booster Module (Without Retail Package)The four-in-one amplifier board uses small tips:1. When using as a UPS, the SW pin should be shorted, the output should be stored in real time, and the power can be turned off to start the battery at any time.2. As a mobile power source, it can be connected to a SW switch, it is turned off when not in use, has no static loss, and is very energy-saving.3. If the SW does not want to connect the switch, it may also be shorted and the output indicator will be soldered when all tests are completed. This can reduce current consumption by ten or twenty mA without affecting the normal output of the circuit, and compare energy saving.4. During the operation, it is possible that the board will enter the protection state and will not be output for various reasons (errors, incorrect connections, etc.). Once the problem is resolved, the charging port of the hob can be connected to 5V charging and the hob is powered again. Re-output can be activated.5. Special Use (Very Special): If you want to supply 5V for the load when there is an external 5V, 3.7V (without gain) power supply for the load directly from the lithium battery, when there is no external power supply, you can connect the positive output line of the board directly from the s-pad pin SW wire. Loads.6. The 5V power supply used by individual users internally uses a high-capacitance output capacitor. This capacitor can continue to discharge when the power is turned off so that the power supply voltage slows down the process, which will turn off the power to the board. I didn't change the battery power quickly. If you encounter such a situation, please to provide a free solution.