The 501-27519-13 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 10 MHz, Supply Voltage 15 V, Phase Noise -160 dBm/Hz@100 Hz to -140 dBm/Hz@10 Hz, Phase Noise 1 kHz -167 dBm/Hz, Phase Noise 10 kHz -170 dBm/Hz. Tags: Module with Connectors. More details for 501-27519-13 can be seen below.