Spring Mattress Construction: Features a durable spring system that provides reliable support and comfort for restful sleep.(When you open the vacuum packaging bag, be careful that the mattress will quickly rebound)Memory Foam Comfort Layer: Incorporates memory foam technology that contours to your body shape for pressure relief and personalized support.Hybrid Design Benefits: Combines the responsive support of traditional springs with the conforming comfort of memory foam for optimal sleep experienceSupportive Sleep Surface: Combines spring coils with foam layers to deliver balanced support and cushioning throughout the night.Specifications Item firmness description: Medium Top style: Smooth Top Fill material: Memory Foam Special features: Breathable, Durable, Edge Support, Pressure Relief Construction type: Memory Foam Item Thickness: 25 Centimetres Details by option Double (4'6") · 25cm, Small Double (4') · 25cm, Single (135 x 190cm) · 25cm Size: Double Product dimensions: 190L x 135W x 25Th centimetres Item weight: 22 Kilograms Product benefits: Edge Support, Motion Isolation, Pressure Relief Item Dimensions L x W x Thickness: 190L x 135W x 25Th centimetres Double Size Dimensions: Measures 190cm in length, 135cm in width, and 25cm in height, suitable for double bed frames King (5') · 25cm Size: King (U.K. Standard) Product dimensions: 2L x 1.5W x 0.25Th metres Item weight: 26.6 Kilograms Product benefits: Pressure Relief; Edge Support; Breathable; Durable Item Dimensions L x W x Thickness: 2L x 1.5W x 0.25Th metres King Size Dimensions: Measures 200cm in length, 150cm in width, and 25cm in height, suitable for double bed frames,