diymore 10pcs Mini Digital Voltage Meter DC 2.5~30V 0.28" 2 Wire Digital Voltmeter Gauge Tester Green LED Display Panel Mount Car Motorcycle Battery Monitor Led
 
Product Features
  

         
Two wire connection, with reverse polarity protection.
         
Two-wire measurement range: DC 2.5-30V(Red), 2.6-30V(Yellow/Green), 3.2-30V(Blue).
         
Small in size and light in weight,quite easy and convenient to carry out.
         
Max. Input Voltage:DC 30V(Higher than this voltage is has a risk of overburning).
         
The precision automatic adjustment ,when less than 10V accurate to 0.01V, more than 10V accurate to 0.1V.