Armstrong Contract Mattress 13.5’ gauge spring system provides even weight distribution from the heaviest parts of the body. The spring provides a softer feel, which gradually gets firmer as pressure increases, without sacrificing comfort. The whole spring unit is twice tempered to set the springs and make them stronger Smaller diameter allows more springs per mattress than conventional beds and increases the comfort life. High density foam strip placed inside the edge of the mattress springs which prevents the mattress from sagging and gives both longer life to the mattress and a firmer sleeping area. Edge Guard gives edge to edge enabling the sleeper to sleep right up to the edge of the mattress.