Constructed of .25mm PVC for superior strength and long-lasting durability. The 3-tiered rectangular design has a center air-release chamber to prevent rocking and a self-sealing air intake valve for easy stress-free inflation. Inflate with 2-3 puffs of air by mouth. Easy to deflate and carry in a pocket, purse or backpack. GREAT GIFT IDEA for any sports fan, grandpa or grandma, mother with children active in sports, hunters, boaters, hikers, frequent travelers, and those suffering from lower back pain or tailbone pain. TRY ONE TODAY!