I believe that is a Swivelwheel 46.
SWIVELWHEEL-46
Kinda heavy and can be a bear to manuever around when not hitched up.
I would suggest the Swivelwheel ECO fer the platform of choice if yer making a boat tail setup from their available trailers.
SWIVELWHEEL-ECO
I believe their torsion bar setup will have a tendncy to bounce unless heavily loaded down like all the other single wheel platforms being manufactured today.