This is the model that has been so popular over the years. Six permanent drill hole sizes: 3/16", 1/4", 5/16", 3/8", 7/16", & 1/2". Self-centering action, 2" width capacity...round or square stock. Popular with vocational schools and woodshop classes because of its ease of use and durability. No loose parts to get lost. This tool will give many years of trouble-free use, with just some basic care. Metal jig.