Widely Application: Suitable for professional and amateur vertical testing in decoration,construction, and other fiolds.The plumb bob with magnetism can provide strong fixing ability on iron surface, cement wall, plasterboard and wooden surface, making the work easier. Quick Stabilization: Plumb bobs retractable?through resistance adjustment, it can adapt to different specifications of plumb bobs (5oz-16oz), and can ensure that the balance can be quickly maintained.Just lift the plumb bob and the line will retract automatically. Multi-Surface Connection: When working on iron surfaces, the magnetic block of this plumb bob can beused to adsorb onto the iron surface.When working on wooden or other surfacos, a positioning pin can be used to fix it to thewoodcn surface. Method of use: During use, maintain a certain distance from the wall and pull down theverticality. By measuring the distance between the line and the wall from bothends,it can be determined whether the wall is vertical. Adjustable Resistance of cord: You can also freely choose diferent specifications of lead hammers(150-400g/5,29-14,110z),and the lead canautomatically maintain balanee within a few seconds stop. Safety lock buckle: When not using a fixed needle, the safety lock can be locked in the "ON" position to ensure safety.