BIRD TECHNOLOGIES' 25E-400 table 1 standard element 7/8 in line section. 400 – 800 MHz, 25 W. For 43 and 43P general purpose wattmeter, 4391A REP-dual element, power analyst, 4314C PEP single element wattmeter, 4431 variable RF tap wattmeter, and 3170B dual meter-dual element.