This T-Rule allows you to scribe with zero uncertainty guaranteeing that the precision built into the Incra T-Rule actually shows up in your finished work. One edge is ruled with guide holes at 1/32" increments. The other edge is ruled in 1/64" increments. The end is ruled in 1/64" increments for making vertical measurements such as adjusting saw blades and router bit heights. The center has a slotted 1/16" rule, a slotted 1/32" rule and a 1/64" rule with guide holes for fine dot marking. The beam length is 5" and blade width is 3".