Empire 581 Series Magnetic I-Beam Level, 48" Long, Aluminum, Tri-Vial: * Square it away: advanced I-beam-frame design ensures accuracy * Tri-vial versatility makes it possible to get plumb, level and 45 degree angle readings * Top-mounted level-vial window provides a convenient, second vantage point * Magnetic base enables hands-free use on ferrous-metal materials * Level Type: Carpenter/Mason * Leveling Axis: 45 degrees * Horizontal/Vertical