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These vintage swim trunks were made by Arrow (yes that Arrow- the one that made shirts and ties) in the late ’40s or 1950s. They have an atomic / Hawaiian seashell print on the front panel, and a woven satin- type fabric on the back- probably some kind of acetate blend. The front is lined and they have a key pocket and drawstring waist.
Waist unstretched: 11″ (doubled = 22″)
Waist stretched: 17″ (doubled = 34″)
Side Seam: 8-1/2″