This rib textured one-shoulder swimsuit brings playful fashion to your beach swimwear wardrobe. MARKS & SPENCER Ribbed One Shoulder Swimsuit. Sizes UK 6 / 12 / 14 / 16. 83% polyamide, 17% elastane (exclusive of trimmings), Lining - 92% polyester, 8% elastane, Padding - 100% polyurethane.