irreparable damage to the product. Measuring range: 5-100V Power supply range: 5-100V Minimum start-up: 3.8V Allowable error: ±1% Input impedance: >100K ohms Operating current: red <100mA, green <12mA, blue <12mA Refresh speed: approx. 300mS/time Display method: 3-digit round LED tube Display colour: red, green, blue optional Lead wire length: 20cm Overall dimensions: 33.8 diameter Opening size: diameter 30.3 Operating temperature: -10℃~65℃