Big Gator Tools BGT V-4 Pack V-Drill Guide SAE + Number Hole Sizes 4pc Kit Includes: (1) STD500NP, (1) STD1000DGNP, (1) STD2000DGNP & (1) SDGMINI Special nickel alloyed steel heat treated for durability. Non-plated material with light oil coating to prevent rust. Centers the holes on pipes, dowels & outside corners. Flat side allow 90 drilling into flat surfaces-just clamp and drill.. Automatically squares up the drill with the surface. Alignment marks on both sides, to line up on center. Bottom surface is precision ground to ensure stability & accurate perpendicular alignment on flat surfaces. Round stock hole alignment marks on one side. Prevents drill bit wander. Portable, pocket-sized and housed in a handy plastic storage case w/surface ridges to prevent opening, PegBoard-Friendly. Only shipping one of each V-Drill Guides "NO" other tools or ruler included