Manufactured on NASA Technology.Reacts to body heat. Responds and supports the body.Pressure and Stress relieving. Anti-Dust mite and Hypoallergenic.Comes with a removable, dry cleanable cover. Helps promote good blood circulation.Available in Regular and Firm Tension.Handmade in the UK conforming to the British standards by using high quality materials and components.The Happy Beds Stress Free range is made from a unique high density Visco-Elastic Polymer Gel. Originally designed for NASA missions, it is soft and pliable, following the outlines of your body perfectly. It reacts to your body heat and weight. The extraordinary features help blood to flow and circulate freely, preventing the nerves and muscles from numbing.Relieves:Headaches. Stiff neck. Backache. Joint pain. Rheumatic disorders. Circulatory problemsThis product is vacuum-packed for your convenience. The mattress is compressed to a much smaller size, which facilitates storage and installation.Please take great care in opening the mattress packagingOn opening the second layer of vacuum-sealed packaging, the mattress will immediately start the process of recovering to its natural depth and shape. Please allow approx. 4 hours, and the mattress is fine to use the same day once opened.Specifications (Select your choice of mattress size from the drop-down list above): Depth: 150mm (8") 3ft Single: Width: 90 cm (3') Length: 190 cm (6'3") Weight: 18 kg 4ft Small Double: Width: 120 cm (4') Length: 190 cm (6'3") Weight: 21 kg 4ft6 Double: Width: 135 cm (4'6") Length: 190 cm (6'3") Weight: 23 kg 5ft King Size: Width: 150 cm (5') Length: 200 cm (6'6") Weight: 25 kg 6ft Super King Size: Width: 180 cm (6') Length: 200 cm (6'6") Weight: 27 kg Note: Sizes and Weights are approximates and may vary slightly.