Carpet Cutter/Drill Guide 3/8 In (9.52mm) Hardened Steel Serrated Blade Stainless Steel Beveled Construction Bores A Clean Hole In A Carpet And Serves As A Drillbit Guide To Prevent Carpet Snags And Snowballs Can Be Used On Any Floor Carpet The Drill Guide Accommodates Up To A 7/16 In Bit And Protects The Carpet While Drilling Through Sub-Flooring For Use With Power Drills