Lee Shaver Hadley Eye Cup for High Grade Pedersoli sights with 5mmx.5 threads (metric thread). 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 purchase is correct before you install it. There will be no returns on damage eye cups (cross threads etc.).