The 25B measures CW, FM and AM frequencies from 10 Hz to 20 GHz. The 25B counter offers EIP's unmatched performance in a compact, affordable package. Even in a 3.5" tall half-rack sized instrument, all the benefits of EIP's YIG filtered front end are still available. Standard features include frequency selectivity (high and low frequency limits), power measurement in Band 3, GPIB,and 200 watts input protection.