First line: ACT303K/303.875/TO39 true one-port, surface-acoustic-wave (SAW) resonator low-profile metal TO-39 case. provides reliable, fundamental-mode, quartz frequency stabilization i.e. transmitters local oscillators operating 303.875 MHz. 1.Package Dimension (TO-39) Dimension Configuration Input Output OutpAbstract: .. The ACT303K/303.875/TO39 TO39 is a true one-port, surface-acoustic-wave SAW resonator in a low-profile metal TO-39 TO-39 case. It provides reliable, fundamental-mode, quartz frequency stabilization .. Tags: ACT303K 303