The 303B from KRYTAR is a RF Detector with Frequency 100 MHz to 40 GHz, Max Input Power 20 dBm, Max Input Power 0.1 W, Voltage Sensitivity 0 to 0.5 mV/mW, Capacitance 3 pF. Tags: Connectorized, Diode Detector. More details for 303B can be seen below.