Levels, bubble levels, spirit levels, and goniometers are all tools used to measure angles or inclinations. In production, they can confirm the flatness of equipment or panels. In construction and decoration, they can measure inclinations or slopes. Some photographic equipment must also be embedded with a bubble level for horizontal adjustment. In addition to the general bubble type, there are also three-phase bubble types and digital electronic types for fast and accurate measurement. Some products have magnetic bodies for magnetic measurement.