Hi-Tech Performance (HTP) Top Loader is made from HF-1173-D 4130 annealed steel and is one of the strongest in the market.  The HTP top loader can be used with the Meirsch, MPD, Dominator, Berkeley, and American Turbine intakes.
 
Caution:  The Top loader is the single hardest working part on a jet boat.  If and when a loader fails, damage to the boat and human injury is common.  Inspect your loader often.  Replace if you dont know the age or history.  Forming rust and poor welds are a bad sign.