The 501-26745 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 10 - 100 MHz, Supply Voltage 15 V, Phase Noise -137 dBm/Hz@100 Hz to -116 dBm/Hz@10 Hz, Phase Noise 1 kHz -151 dBm/Hz, Phase Noise 10 kHz -174 dBm/Hz. Tags: Module with Connectors, Thru-Hole. More details for 501-26745 can be seen below.