Humminbird AS GPSAS GPS The AS GPS is an adapter cable that allows APEX chartplotters to connect with a Humminbird external GPS receiver. Combined with an external GPS receiver, users will get extremely accurate position readings with AS GRP receiver (sold separately), or choose to get both accurate GPS readings and a constant compass heading with AS GPS HS (sold separately). AS GPS cable measures 30" in length and connects to the MFD via a waterproof, twist lock