The 501-27500-02 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 5 MHz, Supply Voltage 15 V, Phase Noise -155 dBm/Hz@100 Hz to -135 dBm/Hz@10 Hz, Phase Noise 1 kHz -165 dBm/Hz, Phase Noise 10 kHz -165 dBm/Hz. Tags: Module with Connectors. More details for 501-27500-02 can be seen below.