Abstract: A cylinder cutting blade for a lawn mower that includes at least two modular cylinder cutting blade sections. Each modular cylinder cutting blade section effectively being a short cylinder cutting blade which are rotationally connected together in succession in such a manner that rotation of one modular cylinder cutting blade section results in rotation of the other modular cylinder cutting blade sections. Each modular cylinder cutting blade section includes a longitudinal axis, a plurality of cutting bars which spiral around the longitudinal axis, a frame to hold the cutting bars in their respective positions, and a locking mechanism. The locking mechanism of each modular cylinder cutting blade section interacts with the locking mechanism of adjacent modular cylinder cutting blade sections to rotatably lock the modular cylinder cutting blade section to the adjacent modular cylinder cutting blade sections.

Abstract: An optical collimator device for use in aligning a gun bore with a gun sight is formed of a graticule and lens which are located within the optical collimator device housing. The optical collimator device is mounted on the end of the gun barrel with a magnetic bar and rail structure formed in the optical collimator device housing and this magnetic bar and rail structure allows the optical collimator device to adjust vertically for use with guns with low sights and with raised sights and large bore diameters such as shotguns and baton guns.