The Firecore toolbox level is a 9 inch long spirit level with one level, one plumb, and one incline vial for determining horizontal and vertical plane as well as incline. A magnetic base adheres to metal surfaces and provides reliable seating when leveling round items such as pipe, conduit, and shafts. The frame is molded plastic for light weight and has rubber end caps that absorb impacts to help protect the vials and frame. Levels are instruments that are used to determine the true horizontal or vertical plane of a surface. The most common type of level is the spirit level, or bubble level. Spirit levels have a liquid-filled, bowed tube (also called a vial) with a bubble that moves when slight adjustments are made to the level. When the bubble settles between marked points on the vial, it indicates that a surface is horizontally or vertically straight. Levels can have one or more vials to determine the horizontal plane, the vertical plane, or various points between, such as a 90-degree angle, simultaneously. Some levels include a laser line indicator that projects a horizontal or vertical beam on a surface. Bullseye levels, or surface levels, are circular, flat-bottomed spirit levels that determine whether a surface plane is level. Machinists? Levels can range from highly-complex and accurate machines, such as those used in the surveying and construction industry, to precision instruments used in carpentry and other building trades, to simple, pocket-sized devices for do-it-yourself projects.