ToolBarn.com

Levels measure the angle of a surface, and can tell you if that surface is horizontally level or vertically plumb. Manual levels (as opposed to laser levels) feature bubble gauges to measure 90, 45 and 0-degree angles. There are specialty levels like torpedo levels, box levels and I-beam levels, each designed for specific professions like carpenters, electricians and masons. Plumb-bobs are frequently used with a level to establish a vertical plumb line.