This fitting is a "fits-all" fitting because matching dust collection to the various size connections on miter saws, circular saws, orbital sanders, belt sanders and more is never an easy task.

Once you've decided which "step" fits your application best, cut the excess smaller diameter material off with a knife because as the outside diameter grows larger, the inside also grows larger to allow more air flow.

Care must be taken when cutting the soft PVC material. Flex the excess material away from the cut to take side gripping pressure off the cutting blade. If you've ever cut a garden hose off, it cuts similar to that.