Portable Drill Guide for 17 metric drill sizes: 3, 3.3, 3.5, 4, 4.2, 4.5, 5, 5.5, 6, 6.5, 6.8, 7, 7.5, 8, 8.5, 9, 9.5mm. Heat treated for durability like drill bushings. It?s like having a portable drill press anywhere! Straight perpendicular alignment wherever you go. Drill Straight - Every Time!PROP 65 WARNING: This product can expose you to some kind of chemical, which is known to the State of California to cause cancer.