This cushion consists of 2 different gel densities. The blue part provides pressure relief on vulnerable bone areas, while the transparent gel increases the contact surface with the skin. PE cover, polyurethane gel. Available models: - 41 x 41 cm: Thickness 2.5 cm. Covers : 2 in PU. Weight : 3,1 kg - 43 x 43 cm : Thickness 2,5 cm. Covers : 3D + PU. Weight : 4,2 kg - 45 x 45 cm : Thickness 2,5 cm. Covers : 3D. Weight : 4,5 kg 2 years warranty. Made in France. Resistance : 100 kg.