The 501-27004 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 476 MHz, Supply Voltage 15 V, Phase Noise -108 dBm/Hz@100 Hz to -78 dBm/Hz@10 Hz, Phase Noise 1 kHz -138 dBm/Hz, Phase Noise 10 kHz -168 dBm/Hz. Tags: Module with Connectors. More details for 501-27004 can be seen below.