The 501-26636 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 320 MHz, Supply Voltage 15 V, Phase Noise -118 dBm/Hz@100 Hz to -88 dBm/Hz@10 Hz, Phase Noise 1 kHz -141 dBm/Hz, Phase Noise 10 kHz -152 dBm/Hz. Tags: Module with Connectors, Thru-Hole. More details for 501-26636 can be seen below.