BIRD TECHNOLOGIES' 3127-040, 5/10/25 kW, dual 4-1/2 in rectangular meters on panel 100 µA rigid line wattmeters form a complete power measurement system when combined with the appropriate rigid line section and plug-in elements.brbrPlug-in elements must be ordered according to the desired frequency and power ranges, the meter scales and size of the line section selected for use with the meter. 25 ft DC cable