Patent attributes
A level of the type having an elongate hollow frame including two sidewalls each defining axially aligned vial openings into the frame. A vial casing is secured with respect to the frame and defines a hermetically sealed single-cavity casing interior entirely enclosing a liquid-and-bubble vial with a substantially cylindrical outer surface extending between two vial ends. The casing is formed of two opposite round face-walls and a surrounding cylindrical wall therebetween. The cylindrical wall has a pair of opposed major wall-portions of first thickness and a pair of opposed intervening wall-portions of second thickness greater than the first thickness. Each intervening wall-portion defines a recess which snugly receives a corresponding one of the vial ends. The inner surface of the surrounding wall is smooth and substantially free of light-ray-interfering structures, whereby the vial appears embedded in the surrounding wall and the face-walls provide uninterrupted full views of and about the cylindrical vial.