The QDA-2000-4000-63.75-0.25 from Qualwave is a RF Variable Attenuator with Frequency 2 to 4 GHz, Attenuation Range 0 to 63.75 dB, Attenuation Accuracy ±1.5 dB, Insertion Loss 2 dB. Tags: Digital. More details for QDA-2000-4000-63.75-0.25 can be seen below.