Will a Garmin 18 xHD mount directly on this?

The 5" tall Seaview forward leaning mount is for Open Array Radars, Closed Dome Radars and small Satdomes (16" diameter or smaller). It looks like Your Garmin 18 xHD Is 18". The Garmin 18" is too large for this mount, a top plate is required for use with this mount.