The 501-27388 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 6400 MHz, Supply Voltage 15 V, Phase Noise -90 dBm/Hz@100 Hz to -60 dBm/Hz@10 Hz, Phase Noise 1 kHz -116 dBm/Hz, Phase Noise 10 kHz -137 dBm/Hz. Tags: Module with Connectors. More details for 501-27388 can be seen below.