Here we have a vintage new old stock, American-made scissor link expansion band by Kestenmade.
It measures 5 1/4 inches at rest from end to end where it attaches to the spring bars and gives plenty of stretch. The end pieces measure 16mm, and the band itself is just under 13mm wide.
This beautiful gold-tone bracelet is in excellent condition, save for some minor shelf wear from storage over the years.
It’s obvious this bracelet has never been on a watch!