The QPDO-I-100-3.9 from Qualwave is a Phase Locked Oscillator with Frequency 3.9 GHz, Output Power 13 dBm, Frequency Stability ±0.2 ppm, Reference Frequency 100 MHz, Supply Voltage 12 V. Tags: Module with Connectors, PLDRO. More details for QPDO-I-100-3.9 can be seen below.