[slipfit]

Tiara does not make the sending unit or the tank it mounts into.

Your best bet is to jump into the rear hatch and look for a manufacture tag on the tank.  Contact the manufacture with the model number of the tank and they will offer a direct replacement, and usually for much less without the Tiara markup.

I replaced mine a couple years ago.  If I remember correctly, my tanks were made by Florida Marine Tanks and they set me up at a reasonable cost.