Only works in the down position as there is a large locking mechanism on the back of the riser/lower bar that locks the balls in place. When the lock was installed in the vertical position, it pushed the hitch out so the tongue didn't enter the receiver. Once you discover it and wish to return it, the seller on this marketplace will charge 20% "REPLACE COMMISSION" AND POSTAGE. If you don't know what you need and what's right for you, you can avoid this third party and their restocking fee policies. There are better products and much better sellers.