Vispring coils are made in-house from fine Vanadium steel which makes the coils very hard, rust-resistant, and long-lasting. These premium coils are carefully hand-nested inside natural calico pockets in a honeycomb pattern. This pattern prevents gaps between the coils so that the support is equal throughout the mattress. There is even, firm, and constant support for your entire body. Mattresses come with a single, double, or triple layer of springs, allowing you to prescribe what will work best for your comfort.