The 501-27252 from Quantic Wenzel (Wenzel Associates, Inc.) is a OCXO with Frequency 640 MHz, Supply Voltage 15 V, Output Power 16 dBm, Output Load 50 Ohms, Phase Noise -168 to -85 dBc/Hz. Tags: Module with Connectors, Low G-Sensitivity. More details for 501-27252 can be seen below.