US Patent 7150106 Method of using a level

A water or spirit level is composed of an elongated body, preferably of metal, at least one bubble mounted in the elongated body, and end caps, preferably of plastics material, at the end faces of the elongated body, wherein at least one outer surface of the elongated body constitutes a preferred measuring surface. At least one of the end caps is releasably connected to the level body such that the end cap can optionally be removed and once again replaced.