Functionality:
The GPS antenna supplies "raw data", not NMEA data. The antenna is connected in an easy way to the easyTRX (or any other AIS Class B transceiver) If you use the GPS antenna, you nevertheless must have a separate VHF antenna for the easyTRX. 


What is necessary to connect the GPS antenna?
There is no special device or adapter necessary. The antenna is supplied with a 5m long cable and the right plug to connect it to the easyTRX. The cable itself can be extended by a cable extension up to 15m. But, please if you extend the cable, please use a good cable, eg. Aircell 7 or similar and not the regular RG58.

For which Class B AIS the antenna can be used? 
The GPS antenna can be used for every Class B AIS transceiver which needs GPS raw data. (Most of all Class B AIS do need raw data GPS antennas!)