Features： 1、High Accuracy Measurement: Ultra low cost, high accuracy meets most application requirements. 2、Reverse Connection Protection: The power supply has reverse connection protection, and the reverse connection line will not burn. 3、3 Wire DC Digital Display Voltmeter Head: The measuring range is 0V‑99.9V, and the power supply range is DC 5‑30V. 4、High Brightness LED Display: The display devices all use high brightness LED digital tubes, and the display effect is good. 5、High Quality: It is manufactured by fully automatic SMD technology with superb craftsmanship. Specification： Item Type: Digital Display Voltmeter Material: PCB Size: Approx. 48 x 30mm / 1.9 x 1.2in Purpose: DIY Module Measuring Range: DC 0V-99.9V Power Supply Range: DC 5-30V (External Power Supply is Required) Maximum Input: DC 30.0V Allowable Error: ±1%; When Greater Than or Equal to 10V, The Error is ±0.3V; When Less Than 10V, The Error is ±0.10 Display Mode: Three Digit 0.56in LED Digital tTube Wiring: 3 wires, 20cm / 7.9in in length, the black wire is the shared negative pole; the red wire is the positive pole of the power supply voltage (DC 5~30V); the white wire is the positive pole of the measured voltage (DC0~100V) Working Temperature: -10℃~65℃ Package List： 2 x Module