The 501-25398 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 3000 MHz, Supply Voltage 15 V, Phase Noise -98 dBm/Hz@100 Hz to -68 dBm/Hz@10 Hz, Phase Noise 1 kHz -125 dBm/Hz, Phase Noise 10 kHz -143 dBm/Hz. Tags: Module with Connectors. More details for 501-25398 can be seen below.