CURT Receiver Hitch Adapter (2" Shank, 6" Drop, 7,500 lbs.) Model 45808CURT Receiver Hitch Adapter (2" Shank, 6" Drop, 7,500 lbs.) Model 45808 CURT high low hitch adapters and extenders are easy to use and help provide level towing for your trailer. This high low receiver hitch adapter is designed to fit a 2 inch x 2 inch receiver tube opening. It not only extends the receiver but also provides 6 inches of drop or 6 inches of rise. It is great for adjusting the height of a ball mount, bike rack or other hitch