An important add-on for your PTO or power take off is an overrun clutch like this. PTO overrun clutch is basically a ratcheting mechanism, this way is locked, this way it ratchets like a free wheel on a bicycle wheel. This allows a rotary implement like a mower to overrun your PTO shaft, hence the name. We always equip all of our tractors with this, and it slides right on to your PTO shaft, like so, and locks into place. And it's basically a ratchet, like a bicycle wheel. What this does, it allows an implement like a mower that carries a lot of momentum, you have heavy blades that are spinning very fast. If you want to stop the tractor you can press the clutch in, and that would normally bring the tractor to a stop, but the momentum of your blades turning, will keep your drive shaft turning, turn your PTO thereby turning your transmission, and push the tractor forward. So it's an important safety feature, if you want to stop quickly to avoid running into something, you don't want a rotary implement like a mower pushing the tractor forward. This is the device, your PTO overrun clutch that will stop that from happening.