Today we'll be reviewing part number C45426. This is a Curt class 4 extra duty ball mount rated at 15,000 pounds. This is designed to fit 2 1/2" x 2 1/2" trailer hitch receivers. This portion here slides into the hitch. You're going to push it in until your pin holes will line up with one another, and then install a hitch pin and clip or a hitch pin and lock. Those are separately.… see more >