The EFIS-D10A/EFIS-D100's attitude algorithm is normally aided by pitot-based airspeed information. If the EFIS’s airspeed source becomes unavailable, the EFIS will automatically use GPS ground speed to continue to display accurate attitude. In STC-approved installations, the GPS-251 is a required component. In experimental/LSA installations, the GPS-251 will enable GPS ground track mode to the Autopilot when servos are installed.

GPS-251

Discontinued - More Info

Note: In order to not reduce the signal, the GPS-251 module must not be painted.
Note: In STC-approved installations, the GPS-251 is a required component.