Cokin System "A Series" Adapter Rings use for lenses 36mm and 62mm in diameter is recommended for focal lengths over 35mm.
Slide the filter holder on the adapter ring until it snaps in place. The filter holder is now solidly attached to the lens, yet it can rotate both left and right. Slide the filter into one of the filter holder slots. The one closest to the filter holder housing is the narrowest; it allows the use of round filters with notched edges (polarizer, star filters..). The two central slots are intended for square filters. The outer slot can be used either for an additional filter or for a coupling ring.
Adapter rings are available from 62mm - 112mm and will fit diameters up to 118mm with a 4-point universal ring. The X-pro Adapter Ring System benefits from 20 years of experience with the Cokin 'A' and 'P' systems. They fit many different types of lens - large diameter zooms, extreme wide-angle lenses, medium and large format, cinema and broadcasting.
For more information about, Cokin 41mm TH0.75mm Adapter Ring A Series A441A .