Sleeping mattress from Bonnel springs, Foam Ultra, Felt and Foam Plus. Bonnel springs give an absolute sense of support and stability. Foam Ultra, Foam Plus are foam materials of high density and resistance for great elasticity, flexibility and uniformity that ensures the maximum performance of the behavior of the mattress. The mattress is surrounded by fabric with antibacterial certification. 25cm +/- 1cm Hard Foam Ultra Foam Plus Felt Steel Bonnel Springs (384 Springs)** Felt Foam Plus Foam Ultra