Adjustable voltage ,Turn the buck voltage clockwise can directly work with 5v, 9v, 12v, 24v.This package include 5 colours Mini Digital DC Voltmeter,Red: 25V - 30V,Yellow: 26V - 30V, Green: 26V - 30V, Blue: 32V - 30V, White: 30V - 30VDetection voltage: DC 24V 30V. Working current: 30mA.Measurement rate: Greater than equal200mS / times.Operating temperature: -10 +65 Celsius .Installation hole: 23 x 10 mm.Display: 028 inch LEDDimensions: 31 x 120 x 9mm (length x width x height)Accuracy: 03%(+/- 1 word)Working humidity: 1080%Working pressure: 80106kpaColor: photo colourMaterial: plasticPackage Including: 5 x Mini Digital Voltmeter(Red, Yellow, Green, Blue, White)Only the above package content, other products are not included.Note: Light 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.