Irwin 1794064 2550-Magnetic Box Beam, 24"Highlights: Length: 24" 2550 Series Heavy duty, thick walled high grade aluminum frame Durable; resists jobsite wear and tear Over molded rubber end caps provide shock absorption protecting the level's accuracy upon impact and are removable for accurate leveling into corners Continuous edge protects center vial, and allows for continuous scribing Rare earth magnets allow for stronger staying power, providing hands free steel construction work Aluminum