This product is only suitable for computer motherboards, industrial control equipment, testing of measuring instruments and other discrete power supply mainframes or their options. Operational precautions: Avoid using and storing this product in areas that are above the temperature limit, excessive humidity and excessive dust. Do not excessively impact, crush or bend the product. Do not attempt to disassemble this product. No need to charge. Do not work more than 10 seconds (to prevent burning), do not plug in the charging (mains danger), do not plug in charging treasure (lithium ion activity is strong). IT IS USB High Voltage Pulse Generator . It is not a USB flash drive. Please use legitimate charging to test the . 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 that the connection work time is less than 10 seconds. In the limit case, it does not exceed . 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 exceed the above working time. Attention: This product is used for USB interface pressure test, can not be used against the law and ethical behavior!! t. Plug in no effect indicates the pressure strength of the equipment. The effect indicates the low voltage of the device. This is the test of the voltage strength of the device. Whether the device is effective is measured by USB . Just because it doesn't work doesn't mean there's something wrong with the USB . Colour:Gray Material:Metal Package Contents: 1 x USB V3 Voltage Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.