I wanted an adapter to convert my weird shark vacuum clip to a more standardized version of hose attachment. This converts to an ID of 31.75 mm so the accessories required will need to have an OD of 31.75mm. There are plenty out there.

You'll want to print with the circular size down and use supports. As far as the clip is concerned, the original designer recommended taking one off of one of the adapters that came with the vacuum. I think all you'd really need is a spring to print it yourself, but I'll leave that to someone else. Fit is pretty snug as is.