Specialized hobbies have always been a market for specialized gear, and competitive target shooting is a perfect example. Today, we have a set of P.J. O'Hare sight covers form the 1920s or 30s, along with a micrometer sight adjustment tool to show you. The sight covers were to protect the sights form physical damage, but also to protect the carbon blackening on the sight faces from being smudged or wiped off. The sight tool allows precise 1/2 minute of angle click adjustment of the sight on a 1903 Springfield, which is other with just free-sliding. Neat!