Lee Shaver Hadley eyecup for 10-40 thread MVA Soules, C. Sharps Sights and others. These adjustable eye cups have nine openings to choose from and a rubber o-ring around the rim to protect the comb of your stock. Due to the wide variety of sights on the market with different threads, be sure that the Hadley you purhcase is correct before you install it. There will be no returns on damaged eye cups (cross threads etc.).