Faithfull Plumb-Auto Automatic Plumbline 400G (14Oz)The Faithfull quick stabilising 400g steel bob on the Plumb Auto provides an accurate plumb line within seconds. By using either the magnetic panel or the retractable pin, it can be secured to steel, timber or plaster surfaces before dispensing a line to the required length. The Plumb Auto is ideal for all building and decorating applications, and the magnetic feature is an asset when working on steel fabrications where nails and pins are ineffective.