NOTE:This product is used for USB interface pressure test, can not be used against the and behavior!! Only for testing and research, any disputes and adverse consequences shop is not responsible for, please consider carefully buying!!! This product is plugged into the required USB interface. It will automatically discharge. You only need to record the data you need to measure with other measuring instruments while it is discharging. However,it is recommended the connection work time is less than 10 seconds. In the limit case, it does not . Because the product has many components placed on a very small area, the effect is obvious. Under the premise of not being to wait for good heat dissipation (forced cooling), please do not the above working time. This product is only suitable for computer motherboards, industrial control equipment, testing of measuring instruments and other discrete power supply mainframes or their . interface is USB TYPE-A. Not applicable: microusb .Usb typec. Lighting .A pin-intensive interface. Operational precautions: Avoid using and storing this product in areas are above the temperature limit, excessive humidity and excessive dust. Do not excessively impact, or bend the product. Do not attempt to disassemble this product. Safety Precautions: Keep out of the reach of infants and young children. This product does not contain a battery, it generates high voltage during operation (the booster circuit output is fixed at 300V, when the output is connected to the load, the voltage is pulled down to the discharge voltage, the value is 230V, and the error is +/- 30%). Therefore, do not remove or damage the heat-shrinkable tube skin attached to this product (the heat-shrinkable tube has a withstand voltage of 600V). If the heat-shrinkable tube skin is damaged, stop using it. If any abnormal conditions such as abnormal output voltage (too high or too low), abnormal sound, excessive heat or even fire occur during operation, immediately turn off the power. This product is a test instrument for sustainable output voltage based on the Boost boost structure. The input energy is taken from the output of the USB interface itself (5V 1A or higher), so there is no need to charge it , it requires the output capability of the USB interface: the output voltage is 5V, the error is no more than +/- 20%, and the current output is not less than 1A. Doing so may cause the product to malfunction. colour: yellow + silver Material: plastic+metal Package Contents: 1 x USB Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.