The proven design of the Pressure-Tex Cushion is geometrically cut into sections which operate independently. This allows maximum weight distribution and air to circulate freely helping to keep the skin cool and free from pressure areas. Choice of covers. Fitted with Luxury Velour or PU Waterproof as standard (colours may vary. Dartex available at a small extra cost. With Dartex cover (both sizes) plus Fitted with either luxury velour or PU Waterproof cover as standard. Dartex covers available at a small extra cost as below. With Dartex cover (both sizes) plus All above suitable up to 18 stone - over 15 stone please request ?ultravisco?