1. Carbon Steel Plumb Bob: The plumb bob made of carbon steel hangs vertically, with sufficient weight for good vertical alignment and accurate measurement. quality metalforged multifunctional wire pendant, sturdy and durable. 2. Strong Magnetic DesignA powerful magnet is embedded on the side of the plumb bob, allowing it to be easily attached to iron structures for convenient operation. It ensures quick balance adjustment—lifting the plumb bob causes the string to retract automatically. 3. Nylon String: The 4.5m quality nylon string has automatic retraction, is clear, wearresistant, and not easily broken after prolonged use. The selfretracting plumb bob includes an internal flexible spool—simply lifting the hammer lightly enables effortless, laborsaving winding. 4. Adjustable ResistanceThe resistance is adjustable, making this portable plumb bob suitable for different pendulum hammer weights. Adjustable distance measurement can accommodate various building conditions.