With this chrome-plated steel Adapter you can mount any bezel mandrel with a 1/2" diameter handle in holders and workbenches designed to hold ring and forming mandrels. Our Adapter has an outside diameter of just under 1" (0.950"). The inside diameter is bored out to just over 1/2" to accommodate any mandrel with a 1/2" diameter handle, including most Bezel Mandrels on this site (see related products below). The Adapter is flat on one side to engage the set screw of any holder that has one.