The ECX-L27BN-644.5313 from ECS Inc. International is a General Crystal Oscillator with Frequency 644.5313 MHz, Supply Voltage 2.5 V, Current 28 mA, Frequency Stability ±50 ppm, Operating Temperature -40 to 85 Degree C. Tags: Surface Mount. More details for ECX-L27BN-644.5313 can be seen below.