Guide holes are sized for ANSI Standard Ground Thread Metric Taps, A protective plastic storage case is included, Special nickle plated alloy steel is heat treated, Precision ground base to assure stability and accurate perpendicular alignment on flat surfaces, V-groove on bottom allows for perpendicular alignment with all tap sizes on round parts or corners, Picture shows top and bottom of guide, Price is for individual V-Guide, Great Quality This new patented metric size tap guide design is easy to use, Tap Straight - Every Time, Can handle tap sizes: 1, 6, 2, 2, 5, 3, 3, 5, 4, 5, 6, 8, 10, 12, 14 and 16MM, Dimensions: 5L x 1, 125H x 1, 125W, SKU: BGTRL004