The 501-26961a from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 400 MHz, Supply Voltage 15 V, Phase Noise -120 dBm/Hz@100 Hz to -90 dBm/Hz@10 Hz, Phase Noise 1 kHz -147 dBm/Hz, Phase Noise 10 kHz -169 dBm/Hz. Tags: Module with Connectors. More details for 501-26961a can be seen below.