Unlike an ordinary circular spring system, Miracoil's unique shape has twice as many springs offering improved pressure relief, edge-to-edge support for maximum sleep space, and zoned support right where you need it most. Featuring eco-comfort fibers, this mattress is good for you and good for the environment, as its comfort layer is made from 100% recyclable plastic bottles which offer breathability and enhanced comfort for a more refreshing night's sleep. Tried and tested Miracoil®'s spring system also has enhanced durability providing superior comfort over many years. Brand Name: Silentnight. Size: Double (4'6)