The 50B-053 from JFW Industries is a RF Variable Attenuator with Frequency 0 to 1909 MHz, Attenuation Range 0 to 101 dB, Attenuation Accuracy +/- 0.5 dB, Power 5 W, Insertion Loss 1.5 to 2.5 dB. Tags: Module with Connectors, Pushbutton. More details for 50B-053 can be seen below.