How do self leveling laser levels work?

A leveling laser requires the operator to manually level the unit by turning the thumbs screws and looking at the bubbles. A self-leveling laser can find and maintain a level.A manual leveling laser requires that the operator manually level the unit by turning the thumb screws of the units and obtaining the leveling unit by observing the bubble bottles. An automatic leveling laser finds and maintains a level within a specified range.