1000 Pocket Springs in a King Size Cotton Felt Soft White Fibre Lambswool Firm Tension Hypo Allergenic 2 Rows of Side StitchingFrom Relyonfts Traditional Collection comes the fantastic Salisbury Ortho. This mattress contains 1000 pocket springs in the 5ft model. Pocket springs are individual springs, each encased in their own fabric pocket that work independently from one another like pistons to conform to the shape of the body. This helps to support the areas of the body that need it the most, helping to relieve pressure and tension. The Salisbury Ortho features a wealth of comfortable fillings such as cotton, wool and soft, white fibre fillings which are sure to provide you with a relaxing night sleep. This firm tension mattress is also hypo-allergenic, ideal for any allergy sufferers. This Relyon mattress has air vents which run along the perimeter that allow for a circulation of air to flow through the matt, reducing moisture and humidity. The Salisbury Ortho also features flag stitched handles which help when turning the mattress. This mattress would be perfect for a whole host of frames and divan bases we have available on our website.