Panel mounting voltmeter 2 wire 

Display: 3 Digits LED

0.56 inch 

needs no external power 

Measuring voltage range 4.5V-30.0V

Precision: 1%

Operating Current: less than 20mA

Input impedance> 100K ohms

Refresh speed of about 300mS 

Display Color: Green

Operating temperature -10 ℃ ~ 65 ℃

Size: Approx. 48x29x22mm/1.81x1.14x0.87"

Dimensions: 48 x 29 x 22 mm(LxWxH)

Mounting hole: 46 x 27 mm

Net weight: 18g

Red wire:  +ve

Black wire:  -ve