G-S CY581 Watch Crystal for Longines 4907

This is a vintage G-S watch crystal, still sealed in its original paper packaging. It's a CY581 model specifically designed for a Longines 4907. The crystal measures 19.9 by 15.9 mm and has that classic tonneau shape. It's a great find if you're doing a restoration on an old Longines and need an authentic replacement part. New old stock.