Olee Sleep 8 Inch 4 Layer Air Ventilation Memory Foam Mattress (Twin) 08FM01T 3.5 inch High Density Foam Convoluted Layer helps make flow to ventilate air 2.5 Inch ILD 28 Density 29 Pound Foam supports your body and disperse Weight 1 inch Memory foam mould your body shape. 1 inch HD foam support your back Line. Small Parcel will be delivered with compressure technology