Two-wire Circular Voltage Monitors DC 4-100V Digital Voltmeter Head Volt Tester

Features: Use: It works for DC 4-100V, mini size and easy to install, work great for checking voltage. Large display: 3-digit LED digital tube, large numbers, quickly and easily read. Opening hole: The opening hole diameter is 30cm, easy to install. It is made from good quality plastic, which is durable, long lasting. Reverse connect protection: It can be protective when connect the wire inversely or wrong. Compact design: It is compact, mini size and portable, easy to store and carry. Package Includes: 1x Volt Detector Specifications: Material:Plastic Size:Approx.3.38x3.38x1.8cm/1.33x1.33x0.7inch Color:Red/Green/Black Measuring range 5V-100V Power supply range 5V-100V Minimum startup 3.8V Allowable error 1% Input impedance>100K ohm Working current red