We've been building a complete GRT dual system that has included compatible com radios, navs, gps, eis, audio pnl, auto pilot and transponder in our RV7a. The GRT staff has been incredibly available to help us with the integration of each of these systems. They have supplied exceptional documentation and wiring schematics that have helped us with each step. I can only give the highest recommendation for a company that supports you all the way.
