The HP Agilent 353A Patch Panel contains a precision 110 dB attenuator and two sets of impedance matching transformers. One set of transformers matches 900, 600 or 135 Ohm lines. The other set of transformers terminates the line in 900, 600, or 135 ohms or in 10 kilohms for bridging measurements. The 353A is used in conjunction with an oscillator and a voltmeter. This combination of instruments is intended for measurements of transmission and system characteristics such as attenuation, frequency response, and gain. Specifications Input: Frequency Range: 50 Hz to 560 kHz, Impedance: 135, 600, and 900 Ohms and Bridging (10 K) Center tapped, Maximum Level: +22 dBm (10 Vrms at 600 Ohms). Output: Frequency Range: 50 Hz to 560 kHz, Impedance: 135, 600, and 900 Ohms and Bridging (10 K) Center tapped, Maximum Level: +22 dBm (10 Vrms at 600 Ohms), Distortion: <1%, Attenuation: 110 dB by 1 dB steps.