The MP05183 from Golledge is a SAW Resonator with Frequency 639.928 to 639.998 MHz, Centre Frequency 639.97 MHz, Insertion Loss 1.3 to 2.5 dB, Voltage 3 V, Operating Temperature -40 to 85 Degree C. Tags: Surface Mount, SAW Resonator. More details for MP05183 can be seen below.