The industry standard is 4 inches so we do not have anything that is 4.5 inches square.
However we do have the Bulldog Square Jack - Drop Leg w/ Non-Spring Return - Sidewind - 26" Lift - 12,500 lbs # BD182700. This is a sidewind leg jack that is 4 inches square.
If you need a new cranking handle you can find one here. Replacement Bulldog Sidewind Jack Crank Assembly w/ Vertical Clevis - 13-1/2" Radius - Black # BD015181
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