The ACTR303K/303.875/TO39 from Advanced Crystal Technology is a SAW Resonator with Frequency 303.8 to 303.95 MHz, Centre Frequency 303.875 MHz, Insertion Loss 1.5 to 2 dB, Capacitance 2.25 to 2.85 pF, Quality Factor Loaded 2000. Tags: Drop In, SAW Resonator. More details for ACTR303K/303.875/TO39 can be seen below.