The MSPD-004-99 from Massachusetts Bay Technologies is a RF Detector with Frequency 18 to 24 GHz, Capacitance 0.09 to 0.35 pF, Response Time 45 pS (Transition), Operating Temperature -55 to 150 Degree C, Storage Temperature -65 to 200 Degree C. Tags: Phase Detector. More details for MSPD-004-99 can be seen below.