The Cosmic Cushion Meditation Cushion may be the most comfortable meditation cushion available. The built-in slop helps create and maintain a comfortable upright posture during meditation. The side extensions help to support the upper thigh and prevent numbness in the legs. The cover is made of durable cotton twill fabric, which is removable and washable. The Cosmic Cushion is available with Kapok fill (cotton-like fiber) or Buckwheat Hull (the outer shell of the buckwheat grain) fill. The fill is contained in linen fabric so the cover can be removed. The Kapok fill provides solid lift and feels soft to the touch. The Buckwheat Hull fill conforms to the shape of the body to provide a solid, grounded feeling. The Buckwheat Hull version has a zippered opening, which allows you to adjust the firmness and height of the cushion. The Kapok version has a compression opening to allow air to escape. It is not recommended that you remove any of the Kapok fill. This REGULAR LIFT cushion is recommended for persons of average height, weight, and level of flexibility. Also available on Amazon in Lowloft, Travel, and Oversize sizes. Please note that the actual fabric color may vary from the image representations.