I believe it is for a half inch arbor but does come with a spacer for a larger shaft.
It is no more than 1/2". I expected about 3/4", but this is narrow.
I'm sure it will as most are designed for a half inch shaft.
Thank you for your recent inquiry with The Home Depot, Jerry. The smallest we carry is .008 wire size, you can view them here: http://www.homedepot.com/s/bench%2520wire%2520wheel%2520fine?NCNI-5 We appreciate your business and look forward to serving you in the future. Thank you for shopping Home Depot.