Balancing soft, cushioned comfort and back and joint support, the Natural Plus 1600 is rated as a medium mattress. In the king-size you�ll find 1600 individually mounted springs, each of which is contained within its own fabric pocket, and provides targeted support. The springs adapt and adjust to your sleeping position and movements. A unique eCool quilt keeps you dry, thanks to its moisture-wicking characteristics, while the EdgeMAX Air system ensures the mattress is well ventilated. A range of natural fibres, including bamboo, alpaca and wool help you sleep at just the right temperature.A 100% natural probiotic fabric treatment keeps your mattress fresh and healthy for longer by tackling allergens, bacteria, and nasty odours, while the no-flip design makes maintenance easy. To extend the mattress� lifespan, just regularly rotate your mattress using the handholds on the side. An 8-year guarantee means your investment is protected for the long-term.?The EdgeMAX Air system strengthens the sides of your mattress while also allowing it to breathe. This unique ventilation technology ensures your mattress remains fresh, while also keeping you cool in warmer weather.The Natural Plus 1600 is topped with the eCool quilt - a layer containing a sustainable smart fibre that boasts excellent moisture-wicking capabilities. By moving moisture from your body to the fabric and drying quickly, the eCool quilt regulates your night-time temperature for improved comfort and a better night�s sleep, even when the thermometer starts climbing!A combination of wool, alpaca and bamboo is incorporated into a layer of natural insulation. This layer helps the mattress keep you cool in the summer and warm in the winter for year-round comfort.