From the ACK website -
What GPS data formats, and baud rates do you’re new E-04 ELT’s accept?
The new E-04 will accept Bendix/King, Garmin aviation formats @9600 baud, or NEMA 0183 input @1200, 2400, 4800, or 9600 baud. The commercial model E-04C also accepts ARINC 429 high and low speed position data.