Just thought I would mention these, as they are sold on Ebay and other places, and thought they work fine and stop any shaft wobble, I have found the larger lower bolt 3/8", in these is not a good stainless steel, and if you use these in the salt water, you will have a problem when trying to loosen or take it off. If you buy one of these, replace the bolt with a quality stainless bolt before you put it on your detector shaft. I learned the hard way.