A Parker-Hale PH5A precision aperture sight, designed primarily for use on Lee-Enfield No.4 and earlier SMLE rifles modified for target and match shooting. The PH5A model is a highly adjustable micrometer sight, offering fine windage and elevation adjustments via precision knurled adjustment drums. It attaches to the left rear side of the rifle's receiver and provides competition shooters and military marksmen with superior sighting capabilities compared to standard service sights.The design allows for extremely fine adjustments, ideal for long-range target shooting — widely used by British and Commonwealth rifle clubs, cadet forces, and some military sniping applications post-WWII. Its robust construction and smooth mechanism were characteristic of Parker-Hale’s reputation for high-quality British firearms accessories.