Though it contains no magnets, this versatile levelling tool attaches to joists, studs, and posts, freeing your hands to position the work and fasten it in place.
U-shaped to straddle nominal 2" stock (i.e., 1 5/8"), it has a small amount of spring to provide clamping pressure, holding securely even in vertical applications (such as plumbing a wall). The vial arrangement also lets you rotate it 90° for use on stock up to 6" square, using the V-notch for registration and the elastic strap to hold it. It can even be used to transform a long, straight board into a level for beams or sills.
Molded from high-impact ABS, it has three level vials and a high-friction grip. At only 8" × 3 3/4" × 2 1/2", it stores easily in a toolbox.