DOUBLE FREQUENCYMETER MODULE

DOUBLE FREQUENCYMETER MODULE .
DOUBLE FREQUENCYMETER MODULE        
Measurement device, it must be provided with two instruments for the comparison of frequencies of two voltagesRange: 2x (45... 65) Hz                                                                                                  
Voltage: 220- 380V with switch                                                                                          
Accuracy class: 1.5
This module must have insulated front panel, 4 mm  safety terminals and one analog meter. One selector shall be included in this panel.
The module must be supplied with manual in English language, Electrical Power Engineering Laboratory