The CURT Industrial Duty ball mount features a 3" x 3" shank to fit heavy-duty 3" trailer hitches. The solid, forged steel construction and I-beam shape supply the necessary strength to complement these larger trailer hitches, and the ball mount has a highly durable carbide powder coat finish for long-lasting rust resistance. To ensure maximum towing power, this ball mount is rated for 21,000 lbs. GTW and 2,800 lbs. TW. The 21K GTW rating is fully tested to at our Detroit engineering facility. This ball mount also offers a rise of 4" and drop of 6" to accommodate larger, lifted pickup trucks, allowing for level towing of the trailer. It also has a 1-1/4" trailer ball hole to accept a heavy-duty trailer ball.