The Duo Sleep 4ft 6 back care double mattress. This mattress is part of the Posture 600 Collection by Vogue Beds. Dual 13 gauge spring unit that has twice the number of springs than a normal bonnell spring unit. Giving better weight distribution whilst still providing that posture feel. Sculpture quilt design on organic cotton fabric. Hypoallergenic fillings which are great for allergy sufferers. No turn mattress with 3 tier stitched border & 4 flag stitched handles.