The EFD500 MFD provides the same great MFD features as the EFD1000 MFD at a lower price, by eliminating the ADAHRS sensor set (and the ability to serve as a PFD backup). It is ideal as a third display to round out your glass cockpit six-pack replacement. The EFD500 MFD can be installed as a slave display to your EFD1000 MFD to make installation a snap.