This is a key piece for Lee system and I am in luck because my UV filter has thread in it and this adapter screws in, without issues. If I had to remove my UV filter every time, other than risking the lens, it would add many more difficult steps to the process and this expensive system would not be all that useful.So if you are going to make this investment, I would say also make the investment in UV filter that has thread and enjoy the Lee system! What a difference maker!However, the downside is that if UV filter is thin, when you want to remove it, so you can put adapter on another lens, it can get stuck to UV filter and its a huge hassle to get it off.






