Walmart offers AquaPro Pool Lounge with Mat for $4.75 (orig. $14.86).  Free shipping with Walmart+ or on orders over $35.

Product Description:

Take a break, lean back and relax anywhere you want with the Aqua Pro Deluxe Go Anywhere Adult Pool Lounge & Backrest with Mat, Blue, Unisex. It provides much-needed support for your head, back, or upper body when you rest against the easily inflatable backrest portion of the lounge. The Go Anywhere Lounge & Backrest folds into a convenient wristlet that also totes essentials such as keys, a wallet and sunscreen so you always have everything you need with you. When inflated, Aqua Pro Deluxe Go Anywhere Lounge & Backrest with Mat measures 52” L x 20” W.

• Ultra-comfortable inflatable backrest supports your head, back, and upper body, For Adults
• Fold & Go Design folds into on-board pouch add keys, wallet, and sunscreen
• Features a ripstop fabric mat
• Take to the pool, beach, or anywhere!
• Recommended age: 15 years and up