The RSR-310.00-250-X from Raltron is a SAW Resonator with Frequency 309.75 to 310.25 MHz, Centre Frequency 310 MHz, Insertion Loss 2.5 dB (Resonant Loss), Capacitance 4 pF, Operating Temperature -10 to 60 Degree C. Tags: Drop In, SAW Resonator. More details for RSR-310.00-250-X can be seen below.