Two way stretch top enables the cushion cells to conform to the individual's body shape without diminishing product effectiveness or therapeutic value * The cover has a stretch Lycra© top material that is a durable heavy weight fabric with a soft feel * The side material is composed of a 3-layered knit polyester spacer fabric which provides superior air circulation that ventilates and cools the user * The fluid proof solid non-skid base material offers a durable easy to clean surface * The cover has the added feature of Velcro© straps placed on the bottom to allow the user to attach the cushion to their chair * Velcro© is a registered trademark of Velcro Industries BV * 18 x16 * Sales are FINAL on all cushion covers * Warranty: 6 Month Limited Warranty