The 501-27516-11 from Wenzel Associates is a OCXO with Frequency 5 MHz, Supply Voltage 15 V, Phase Noise -160 dBm/Hz@100 Hz to -145 dBm/Hz@10 Hz, Phase Noise 1 kHz -165 dBm/Hz, Phase Noise 10 kHz -165 dBm/Hz. Tags: Module with Connectors, OCXO. More details for 501-27516-11 can be seen below.