Ilex nuArc Wide Field Process Lens Paragon 8-1/4'' f:16 Plasmat 2863

there does appear to be some kind of residue underneath the glass and some scratches on the interior lenses see photos kind of tricky to photograph I don't know much about lenses but think this may be for an enlarger or for a large format camera 

measures 4'' x 4'' lens diameter is 2-3/4''