Digital voltmeter red led display DC 0-30V 3 wires Features Reverse link protection. Measurement range: DC 0.00 V - 30.0 V. Power supply: DC 4.50V-30.0V Accuracy: ± 1%. (when  ≥10 V, ± 0,3 V, when <10 V, ± 0,1 V ) Input impedance: > 100 KΩ Maximum working current: 23mA Refresh rate: about 300mS / times. Display: 0.56" dual digital tube ". Operating temperature: -10 ° C - 65 ° C Materials and dimensions Material: PCB LED color: red Dimensions: approx. 48x 29x 22mm Open hole: approx. 46 x 27 mm