Wacoal Bra Fit Guide When you want to slip into something comfortable, try the Wacoal® B-Smooth Brief. The seamless brief is fabricated from a soft and smooth stretch nylon knit that sits at your natural waist. Covered elastic along leg openings for a custom fit. Full rear coverage. Ruching knitted in back-side for comfort. Style # 838175. 93% nylon, 7% spandex. Machine wash warm, hang dry. Imported. If you're not fully satisfied with your purchase, you are welcome to return any unworn, unwashed items in the original packaging with tags and if applicable, the protective adhesive strip intact. Note: Briefs, swimsuits and bikini bottoms should be tried on over underwear, without removing the protective adhesive strip. Returns that fail to adhere to these guidelines may be rejected.