Purchased to fit a Jessem end rail onto a table saw guard. Jessem's product reviewer commented on this application rather than drilling holes and installing a track permanently. That made sense to me, so I ordered a pair when I bought the action manual. They fit perfectly through the 3/4" shank with the included 40mm Forstner bit. After switching on the magnet, they do not move. Easy to turn on and off. I may order a couple or two more for other uses.