High-impact polystyrene frame for durability (unbreakable with normal use).Three high visibility vials (accurate to 0.001 inch) with top view center vial.Ruled edge for accurate measuring (1/8" and 1/16" graduations molded into the level won't scratch or fade).Won't damage surfaces such as wood, paint or tile.Lightweight yet designed for heavy-duty work.Large, high-visibility vials are virtually unbreakable.