DESCRIPTION Highlights: Drill straigh holes all the time Two product v-grooves allow for usage on corners and even cylindrical surfaces The inserted solid metal guide offers the six common drill diameters:  1/8”, 3/16”, 1/4", 5/16”, 3/8”, and 1/2"  Centerlines ensure accurate alignment when drilling into various surfaces Non-slip padding holds the DrillBlock in place while preventing both slipping and marring Cancer and Reproductive Harm - www.P65Warnings.ca.gov.