The ACTR423/423.22/TO39 from Advanced Crystal Technology is a SAW Resonator with Frequency 423.145 to 423.295 MHz, Centre Frequency 423.22 MHz, Insertion Loss 1.3 to 1.8 dB, Capacitance 1.9 to 2.5 pF, Quality Factor Loaded 1700. Tags: Drop In, SAW Resonator. More details for ACTR423/423.22/TO39 can be seen below.