Hultafors 404601 701 Bull's Eye Level

A bull's eye level is a type of spirit level that allows for the leveling of planes in two dimensions — both the 'Pitch' and 'Roll' in nautical terms. Standard tubular levels only consider one dimension. Bull's eye levels are used primarily by carpenters in construction, but can also be found as features of compasses or other devices that need to be kept from tipping in certain directions (whether it be for functionality or precision of measurements). small bull's eye levels are also found incorporated into tripods.