The basic characteristics of the spring mattresses are comfort, strength, durability, airiness and the ability to use on all types of fixed flooring (chipboard, plywood or slate). Sleep & dreams produces a bonnell mattress or pocket spring core. The bonnell core mattresses are made of a 2.2 mm (F1) or 2.4 mm (F2) wire spring. Pocket spring core mattresses are made of a combination of 1.8mm and 2.0mm wire straps, spaced in 7 anatomic hardness zones. We also recommend mattresses with springs for the furnishing of apartments, hostel, hotel and other tourist facilities.