The QDA-4000-8000-63.75-0.25 from Qualwave is a RF Variable Attenuator with Frequency 4 to 8 GHz, Attenuation Range 0 to 63.75 dB, Attenuation Accuracy ±2 dB, Insertion Loss 2.5 dB. Tags: Digital. More details for QDA-4000-8000-63.75-0.25 can be seen below.