The 4813-20B from ARRA Inc. is a RF Variable Attenuator with Frequency 2.9 to 3.1 GHz, Attenuation Range 20 dB, Power 5 W, Peak Power 64.77 dBm, Insertion Loss 0.5 dB. Tags: Module with Connectors, Rotary, Continuously Variable. More details for 4813-20B can be seen below.