A plumb-bob (sometimes called a “plumb-line” or “plummet”) consists of a specially-balanced symmetrical weight, typically with a narrow or pointed tip, which is attached to and suspended from a string to create a vertical reference line.
Once the plumb-bob is suspended, the laws of gravity will act upon it to create a perfectly vertical line that has lots of practical applications such as transferring points, being used as a guideline, or marking lines prior to any building work or cutting.
There are typical plumb-bobs such as the traditional type and others with additional features such as plumb-bobs with magnetic strips or retractable pins, each have specific features which aid them in a variety of tasks.
