I purchased this attachment for my T3 rack because it was less expensive than the iron neck device. I had to experiment with a few different locations on the uprights because I also have lever arms, safety spotter arms and a cable setup with pulleys, but I was able to find an open spot where it works well. The range of motion is defined by the length of the "arm", which forces a relatively short arc or radius. It's a different feel from using a plate against your head while lying on your back or bent over while standing, but you'll get good resistance with the right spacing and height. One negative: comes with a spacer for 2" uprights but is quite loose and wobbly in operation. Moved it to the 3" part of the upright and doesn't rock back and forth when using it.