G-S Flexo MT328 Watch Crystal for Gruen Veri-Thin

Found this vintage G-S Flexo watch crystal, model MT328. It's still in the original paper sleeve. This specific size is 23.3 x 20.0 and was made for Gruen Veri-Thin models like the Guardsman, Medalist, and Air Hawk. Great if you're restoring an old watch and need an authentic replacement part. New old stock.