1, This product is fully functional, you can display the battery voltage, battery , you can also plug directly into the phone or other 5V equipment charging.2, This product is suitable for all kinds of outdoor , mobile , instrumentation and other equipment additional battery voltage display and additional USB to charge the phone and other functions.3, this product uses synchronous rectification step-down chip scheme, low heat, energy saving and environmental protection.4. This product is compact in structure, making full use of space and reducing costs.Colour: Blackmaterial: plasticParameters1, Static input current: 5-25mA, the lower the battery voltage, the smaller the current.2, USB output: 5V/2A (a USB setting for recognition, a setting for recognition)3, USB buck efficiency is up to 96% (because of the synchronous rectification circuit, the buck conversion efficiency is high and the heat is low.4, 8 segment resolution: 10% 25% 40% 50% 60% 75% 90% 100%5, The accuracy of the voltmeter is about 2%6, Working temperature: -10 ~ +65 C7, Working humidity: 10~80% (no condensation)8, Opening size: 45 x 26 x 18mmPackage included:1 X Digital Voltmeter Battery Panel Meter with USB outputOnly the above package content, other products are not included.Note: Light 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.