Here is a small head that will be in constant demand in any shop. Note the wide base bearing surface that assures maximum rigidity even when the bar holder is in an offset position. This wide base design is a Criterion innovation that increases bearing surfaces by 50% over older models. A choice of either 3/8" or 1/2" double hole bar holder with a 1/2" cross hole is available. The unit has a 7/8-20 threaded back and also features a direct reading dial screw.