31mm zwo narrowband set available.
In reasonably good condition - no matter how much you clean you wipe away some debris and end up with some more.
Have images with them for 12 months and experienced no issues or artefacts aside from the standard ZWO halos (hence why I just upgraded to chroma).
Retail at $850 at the moment. Yours for $310 (shipping included) or $300 cash on pickup (2131).
If you want to see some pics taken with this set, check out
https://www.astrobin.com/users/talipova_egan/ or talipov.egan on Instagram.
Photos should give you a good idea of the condition, I've tried to use the light as much as possible to show any imperfections.