The L3A1 Mortar Alignment Sight was developed as a test instrument to ensure that the C2A2 Sight was always reading accurately during use to ensure accurate fire would be applied to targets. Its ideal use would be: before live fire training, operations and whenever the accuracy of the C2A2 Sight is in doubt. The distribution would be one L3A1 per mortar section.
The L3A1 Alignment Sight uses a non - magnifying lens or window to view a virtual project image on a semi silvered mirror. A single vertical line is visible when looking through the eyepiece. A flexible rubber eyepiece cover is provided to prevent rear reflections obscuring the view through the eyepiece with high levels of ambient light