The QDA Series from QuinStar Technology Inc is a Waveguide Attenuator with Frequency 18 to 220 GHz, Average Power 0.3 to 1 W, Attenuation 0 to 25 dB, Insertion Loss 0.2 to 1.3 dB. Tags: Calibrated Attenuator. More details for QDA Series can be seen below.