Display color: Red; Display mode: Three 0.56" LED digital tube; update rate: About 500ms/time; Physical size: 48 x 29 x 22 mm (L x W x H); Opening size: 45 x 26 mm (L x W); Supply voltage: 4~30V; Lead wire length: 14cm (4 lines); Measurement range: DC 0~999mA; Operation temperature: -10 degrees~65 degrees; Measurement accuracy: +/- (1% + 2 words); Note: (please follow the instructions carefully wiring or burn out); 1. The power supply end of the ammeter and measuring the ground USES a total design that is to say the power supply ground wire and test the ground wire is mutually so only string ammeter test end after the electric appliances (both devices being measured between the cathode and tested equipment power of cathode); 2. Advice header power supply to use isolated power supply separately. Instruction of wiring