Definitely worth it. I bought these primarily to use the adapter with my Shark Professional Navigator Lift Away (model UV540). It's not very snug, so if it doesn't work the adapter will fall out when tilted down, but when the vacuum is on the wiggle room doesn't affect suction in any way. It would have been nice if it had a slightly snugger fit, but Shark's mounting options are very limited, so it's nice to find one that's reasonably priced and functional! All fixtures are great.