Dual-layered Vanadium Wire Springs: Wire springs are 2 inches (51 mm) in diameter and come sewn in to individual calico pockets. Innerspring support system is hand formed into a honeycomb- nested unit. For added support and comfort, the Shetland Superb features two layers of vanadium wire springs. British Fleece Wool Upholstery: The Sublime Superb is upholstered in fine British fleece wool for a soft, moisture-wicking sleep surface. Mattress Border: Each Shetland Superb features a border that is 9.1 inches (23 cm) deep and reinforced with 4 rows of hand stitching on all sides. Each side of the Sublime Superb has air vents to promote air circulation and ideal temperature regulation. Borders are upholstered in all-natural coir and wool as a finishing touch, featuring piped ticking for added softness. Custom, Exotic Inner-mattress Fills: Sublime Superb beds are the first of the Vi-Spring luxury line to offer exotic fills that may be customized to your liking. Choose from hand-teased long stranded horsehair, Shetland Isle fleece wool, fine silk, and mohair. A Cover of Your Choice: Cover the Sublime Superb in any of the finest-quality Belgian ticking available through Vi-Spring.