Libra International Ltd manufactures Non-sagging Polyurethane Foam Mattress. Libra International Ltd is an ISO 9001- 2000 accredited company. The Non-sagging Polyurethane Foam Mattress is light in weight and contains a compressed fibre sheet on one side, and high density foam on the other side to give extra comfort. The Mattress can be used on both sides and is available in the thickness of four inches.