The 501-25015a from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 500 MHz, Supply Voltage 15 V, Phase Noise -111 dBm/Hz@100 Hz to -81 dBm/Hz@10 Hz, Phase Noise 1 kHz -136 dBm/Hz, Phase Noise 10 kHz -150 dBm/Hz. Tags: Module with Connectors, Thru-Hole. More details for 501-25015a can be seen below.