Plumb Site offers dual-sided, undistorted viewing in the plumb position and easy, more accurate plumb readings. 1.5" integrated button for easy 1/4" per foot button has a slight radius to ensure it sits securely on pipe. B-Tank valve key provides the ability to open an acetylene tank valve without stripping. Die-cast aluminum body provides extreme durability and strength. Features rare earth magnets which are 5 times stronger than strip magnets and allow for easy, hands-free steel construction work. 9".