A traditional Bonnell spring system enclosed in a 4cm reflex foam. The Bonnel system lends to a strong rod edge to eliminate potential damage .Visco elastic is a clever innovative substance developed originally by NASA to relieve pressure during flight and this can is applied in the same way to the way we sleep taking the pressure from body by sinking gradually with the body creating maximum support and removing the movement creating a restful night.The Bonnell reflex possesses a combination of reflex foam, high density foam and spring system, creating a first class health promoting orthopaedic mattress.