Mattress: Rest your achy joints and sink into this luxurious cooling gel pocket sprung mattress. Medium firm: With a medium firm feel. Sizes: Choose Double, King or Super King. Pocket sprung: Features an extra comfortable and supportive 1500 pocket spring unit. Cooling gel layer: Plus a 30mm cooling gel layer - the perfect antidote to restless nights. Features: Foam-encapsulated side rails, a luxury knitted micro quilted top panel, quilted border and air vents. Cooling Gel Pocket Sprung Mattress | Living Social