The FDR-2-4 from Shireen, Inc is a Frequency Multiplier with Input Frequency 0.85 to 2 GHz, Output Frequency 1.75 to 4.0 GHz, Input Power 10 to 20 dBm, Conversion Loss 14 to 22 dB, VSWR 2.00:1, 3.50:1. Tags: Module with Connectors, Passive, Frequency Doubler. More details for FDR-2-4 can be seen below.