The R1900 from Qualcomm is a SAW Resonator with Frequency 433.92 MHz, Centre Frequency 433.92 MHz, Insertion Loss 1.4 to 1.9 dB, Capacitance 2.9 pF, Quality Factor Unloaded 7000 to 10000. Tags: Surface Mount, SAW Resonator. More details for R1900 can be seen below.