The gel reduces the pressure on the areas at risk. The gel does not leak, does not harden over time, and does not shift under load. PE cover, polyurethane gel. Delivered with a 3D cover and a PU cover depending on the model. Available models: - 40 x 40 cm: Thickness 3 cm. Covers included. Weight : 3,8 kg - 43 x 43 cm : Thickness 3 cm. Covers included. Weight : 4,6 kg - 45 x 42 cm : Thickness 3 cm. Covers included. Weight : 4,5 kg - 42 x 42 cm : Thickness 3 cm. Covers not included. Weight : 4,4 kg 2 years warranty. Made in France. Resistance : 100 kg.