The 8310-138-4-T from Weinschel by Spectrum Control is a RF Variable Attenuator with Frequency 800 MHz to 3 GHz, Attenuation Range 103 dB, Attenuation Step 1 dB, Power 50 W, Insertion Loss 6.0 dB. Tags: Benchtop, Rackmount, Programmable, Digital, Computer Controlled. More details for 8310-138-4-T can be seen below.