27271-3/4446-2 is a part from Johanson Technology, Inc., a manufacturer of ceramic-based frequency control components. The part is a 30.720 MHz ceramic tuned circuit with a tuning voltage of 3.3V. It is constructed using a single dielectric-filled ceramic top that is hermetically sealed and has dielectric resonator material. The package size is ultra-miniature 0603, and the frequency stability is +/- 30ppm over a temperature range of -40C to +85C.