Choosing a filter holder and adapter
When choosing the most appropriate filter holder and adapter for your lens, begin by determining your lens's widest focal length and your camera's sensor size. Refer to the vignette chart to find the best filter holder for your lens that will not cause vignetting at the widest focal length.
Find the proper matching adapter for that filter holder by choosing an adapter thread size that matches your lens barrel thread size.
If you want a "cpl" style adapter, then the adapter-to-lens thread size is the second number. Example: Your lens has a thread size of 77mm, so any cpl adapter ending in 77mm, such as the cpl82-77mm, will fit that lens.
If you want a "slim" type adapter, then the adapter-to-lens thread size is the only number listed on that adapter. Example: Your lens has a thread size of 77mm, so a 77mm slim adapter will fit that lens (there is no "cpl xx" designation for slim type adapters).
To choose between a "cpl" style adapter and a "slim" style adapter, note that the "cpl" adapters have front threads to accommodate round screw-in filters. The "slim" type adapters do not have front threads. The front thread size of the cpl adapters is denoted by the number immediately following the letters "cpl", so in the above example you can screw-in an 82mm round filter into the front of the adapter.