The QSA28A from Qualwave is a RF Variable Attenuator with Frequency DC to 28 GHz, Attenuation Range 0 to 90 dB, Attenuation Accuracy 0.8 to 2 dB, Power 2 to 25 W, Peak Power 0.2 kW. Tags: Module with Connectors, Rotary. More details for QSA28A can be seen below.