NWT Stone Fox Swim Sumatra Bottom Flower Fields XS High Rise Colorful Floral XS Swim, surf, and sunbathe in sustainability. The Sumatra Bikini Bottoms by Stone Fox Swim are created for the everyday beach goer and surf rider. Offering moderate coverage with a slim, high rise fit to accentuate all the places you want most. Made sustainably from 84% recycled poly and 16% spandex, so you can feel good about what’s on your skin.