Experience restful nights with dependable support from a king size orthopaedic Bonnell spring mattress with comfort layers, expertly designed for those seeking a firmer feel and improved spinal alignment. Crafted with a robust 12.5g open coil system, this 4ft6 Bonnell spring mattress for back support delivers orthopaedic strength while gentle quilted fabric and recycled polyester layers offer breathable comfort. Enjoy a hypoallergenic surface that resists irritation, soft to medium firmness, and a convenient rolled and boxed delivery for easy setup in any bedroom or guest space.