Mattress 1700 individually hand nested pocket springs Featuring the unique zonal edge spring system 2 rows traditional hand side stitching Luxurious Cotton cover Layers of lambswool and soft cotton Available in Standard and Firmer comfort levels Fire Test: Conforms to BS 5852 Source 0-1 All zip mattresses can be separated into two single mattresses or zipped together to create one large mattress. The zips are hidden under a fabric layer so no join can be felt when the mattresses are zipped together