I have a New Holland TK100, which is their crawler. I wanted a quick change system because I sometimes use a Rears flail mower on the 3 point and it is no fun connecting. I bought Pat's setupup, read the instructions carefully, called to ask questions when I was installing. Once I had it installed, I could see there were problems. First of all, the angle of the lower arms with Pat's quick change installed was off quite a bit and would not slide in at the right angles to receive the pins correctly. Also the Rears flail has pockets that the Pat's hitch has to fit into. The hook end of Pat's hitch is too big and would bottom out before it went in far enough to connect to the pins. I called Pat's and I explained the problem to the lady that answered. She was very nice but said that there are times when their system will not work. I still wanted to try to make it work so I took Pat's quick connect to a local welding shop and had them cut off 3/4" off the bottom of the hook. The welding shop said that even though my flail mower weighed 2,500 pounds, cutting off 3/4" should not give me any problems. I then went back and reinstalled them, now they clear and do not bottom out. Now my problem is the angle of the unit. The pins do not sit into the hooks at the right angle. My tractor and flail are both cat 3. I am somewhat mechanical so I know I installed their system correctly. So, beware, they will not work on all equipment. Just want to let everyone know so they can be sure they will work and not be as frustrated as I got.