I bought one of these Craftsman 9-24645 Drill Press Work Arbors back in the late 70's.
It's handy for mounting buffing wheels, wire wheels and the Craftsman 9-25246 3" Sanding Drum.
I'm glad I found these here on ebay, as Craftsman seems to have dropped it from their product line.
I ordered two. They're the same great quality as the one I bought 40 years ago.