Specification: Protection mode:wrong reverse wiring,Voltmeter does not work,will not damage Measured voltage range:0 V-100 V DC voltage Display mode:0.000-99.99-100.0; Internal resistance of the head:130K Working voltage:4-30V (recommended range 5V-12V) Refresh speed:3 times/second; Test accuracy:0.3% (maximum error = range X0.003) shell Color:Black Material:PC + metal Product size:4.05*2.3*2cm Package Contents: 1*0.36inch 4 Bits Voltage Meter with shell Note: Light shooting 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. Red/Blue/Green/White Voltmeter Module: Specification: Measuring range: DC 0.000V-100.0V Display mode: 0.36 inch digital tube Power consumption of this unit: 20MA Operating voltage: 4-30V (recommended range 5V-12V) Refresh rate: 3 times / sec Test accuracy: 0.3% (maximum error = range X0.003) Product size: 40.5314.4310.68mm Mounting aperture: 2.9mm Lead length: 20cm Lead definition: red - working power positive, black - common negative, blue - test power positive Package Included: 1pcs * Mini 0.36 inch DC 0V-100V 4 Bits Mini Digital Voltmeter LED Panel Electric Voltage Tester Three Wires Voltage Meter Panel Tester