Need a Little Boost. The Blue Wave Ultimate Comfort Spa Booster Seat delivers that extra level of indulgence to your spa experience. And it is a great option for shorter spa users. The increased seat height allows you to take optimal advantage of the spa jets making the overall spa experience more enjoyable. The booster seat is made of a durable, chemical-resistant textilene material with soft cushion padding to provide maximum comfort. The booster seat includes a removable polyester pouch. Fill with marbles or washed pea gravel and replace in the seat to increase the cushions weight, ensuring it sinks easily into place. Designed for comfort and crafted from high quality materials, the Ultimate Comfort Spa Booster Seat will provide years of enjoyment.