Standard length shank fits Williams Foolproof, Target Foolproof, and 5D only.

SPECS: 7?32"-40 thread. 3?8" or Ѕ" STD Aperture Paks include three, 3?8" or Ѕ" O.D. apertures: one each with .050", .093" and .125“ aperture holes. 7?8" x .050" Target Aperture Pak includes three, 7?8" O.D. apertures with .050" aperture holes. FP and 5D Big Game Aperture Paks contain three, identical eyepiece carriers which are used as large hole apertures for big game.