The Sapphire range features the tried and tested Bonnell spring system, which is centre zoned providing additional support in your lumbar zone. Additionally, the perimeter of the mattress is reinforced with high gauge wire mechanical edge supports ensuring a firm edge whilst preventing ‘roll-out’. In keeping with the Natures Touch ethos, the product is upholstered in a Viscose knit fabric, which is made from natural wood-pulp fibres.