durable and easy to install. Fine workmanship and perfect style. Specification: Product name: AD584LH/AD584JN Voltage and Resistor Reference Module Voltage Reference: 10.000V/7.500V/5.000V/2.500V 4 channels Resistor Reference: 10R /100R /1K/10K/100K Resistor accuracy: Less than0.1% 25PPM Power supply: DC5521 12-30VDC or 23A 12V BAT Operating Current: Less than2mA PCB Board size: 77 X 44 X 22 mm Net weight: AD584LH/AD584JN 20g, AD584LH with case 42g. Applicable object: 4 Digital multimeter Calibration instrument: GWINSTEK -8261A 6Digital multimeter Other functions: With Power switch on/off; GREEN LED indicator Note: 23A 12V dry battery not included in the package. Material: PC+Metal Colour: As shown Package Contents: 1 x AD584 Voltage Reference Module(no box) Only the above package content, other products are not included. Note: Light reflection 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.