The cover is for 62 mm optics. Just measure what the Lumix has. 

hello ， the AI to EOS adapter ring i ssuitable for nikkon AI Mount lens and canon camera body. so you need to confirm your sigma lens specific mount . We care about our customers, any questions, you can ask us directly at customer@kentfaith.com. All emails would be replied in 24 hours, no exception. 

This will work on any 82mm lens. 

I actually have not received this adapter yet. It's shipping from China. Don't think that was disclosed in the ad. However, I do not believe this is for the Pentax Q body rather for digital and film cameras that take the Pentax K mount in its many variations. So I'm expecting to be able to mount my Leica M mount lenses on my digital and film Pentax K mount cameras, no autofocus or relay of exposure information, only to be used with manual focus and exposure. 

A RF lens like a Leica-M lens will NOT focus to infinity on a SLR body like the Nikon. The Leica lens will only focus to a few inches, like a macro lens.