I'm in the process of putting one on my trailer. If you get the bolt on coupler, you need to drill 16 holes 1/2" for the bolts. But you really end up drilling 16 1/4" holes, then 16 3/8" holes then 16 1/2" holes and then cleaning them up with a round file. I went one hole at a time and put the bolt in to make sure it held the coupler in place. There are 2 little rubber bumpers that go between the 2 halves of the coupler so they probably help eliminate the potential noise. It's a heck of a workout drilling all the holes and you probably want to pick up some high quality drill bits.