Widely Used, Professional and Effective: Retractable plumb bob can be used in decoration, construction and other fields. Whether professionals or amateurs, they can use it to accurately test verticality. Its magnetic plumb can be firmly fixed on iron surfaces, cement walls, gypsum boards and wooden surfaces, greatly simplifying the workflow Flexible and Retractable, Fast and Stable: The plumb has a retractable function. Through resistance adjustment, it can adapt to plumb of different specifications from 5oz to 16oz, and can quickly and stably maintain balance. Just lift the plumb lightly, and automatically retract, which is convenient and efficient to operate Multi-Faceted Connection, Flexible Response: When working on the iron , the magnetic block plays an adsorption role and fits tightly to the iron ; when working on wood or other non-iron surfaces, it can be firmly fixed on the wooden using positioning holes or fixing pins, which can easily cope with work scenes of various materials Easy Operation and Accurate Measurement: When using it, keep a suitable distance from the wall and pull down the plumb to determine the verticality. By measuring the distance between the two ends of and the wall, you can quickly determine whether the wall is vertical, and get accurate results in just a few simple steps Optional Specifications, Safety : You can choose different specifications of plumb from 150 to 400g (5.29 to 14.11oz) as needed, and the plumb bob automatically stop stably within a few seconds. In addition, when the positioning pin is not in use, the safety lock is placed in the "ON" position to all-round safety, Manufacturer: Akfldms