Bower 500mm adjustable iris, both gradual or f/settings to f/32 1:8 photographic zoom. "Leather" and felt lined case (shows some wear)included, objective lens is clean, rear lens requires slight cleaning. Over all in very good condition. Threaded mount back for a t-mount to SLR camera. I used this lens to photo Halley's Comet,and still has sticker as a witness of it's visit.