US Patent 9874421 Reticle piece having level indicating device

An improved reticle piece for use in an optical sight, placed at either the first or second focal plane, and an associated method of manufacturing. The reticle piece includes a first portion having a front face, a second portion having a back face disposed opposite the front face, a housing, a reticle pattern on the second portion, and a moveable leveling indicator. The housing includes a spacing element that forms a cavity extending between the first and second portions, the cavity having a perimeter that defines a viewable area of the reticle piece. The moveable leveling indicator is within the cavity and capable of moving along at least a portion of the perimeter of the cavity, possibly moving along the entire perimeter of the cavity.