The 501-27830-01 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 40 MHz, Supply Voltage 12 V, Phase Noise -106 dBm/Hz@100 Hz to -76 dBm/Hz@10 Hz, Phase Noise 1 kHz -151 dBm/Hz, Phase Noise 10 kHz -151 dBm/Hz. Tags: PCB Mount. More details for 501-27830-01 can be seen below.