NOS unused 1950s-1960s old-stock Bellavance stainless steel center scissor-expansion watch bracelet.
This is a rare and high-quality USA made out of production vintage watchband
The ends are curved 3/4" (18.8mm), you can size them to 11/16" or 5/8", see last pic.
Spring bars are included, remember to tell us what size you need.
