The Bewhauler harness is the best, one-size-fits-all carboy carrier we have found. Safe for lifting full carboys. Made of nylon webbing with buckle.
The Carboy Handles are rubber-coated metal and are great for safely handling carboys while cleaning--however they are not intended to carry FULL carboys.
We tend to use both at the same time to make carboy handling as safe as we can.