Glass high quality Circular Polarization Filters for 3D projection double stack. They're pretty big compared to other 3D filters I've seen, too. I put "used" because I don't know if they saw some use or not, but they may be more like "open box." I got them from sort of a dealer's warehouse where some things were used but kept in great condition, while other things were never used, and the dealer didn't always keep track. But the condition is "mint" either way.