You've heard about beds in boxes. But what about beds that rise above the floor 10 inches and then back down? Beds that fold, adjust, and come with temperature control. Beds that move like hospital beds, but have gray upholstery covering the sides making them look modern — similar to the popular foam mattresses that arrive by mail, wrapped up tight like burritos.Made-to-mail mattresses have disrupted the bedding industry. The number of indie mattress brands has exploded since Casper stormed the internet a few years ago with videos showing their beds unfurl from boxes and expand into regular-looking beds in minutes. Traditional mattress retailers have reeled from the onslaught of online competition. Mattress Firm took the latest hit when it closed 700 stores and filed for bankruptcy in October.It's a tough time to be a mattress salesman."Traditional mattress companies are going out of business; they're stuck in the old times," said Ryan Gordon, who markets beds targeted toward aging baby boomers and their elderly parents.As USA Today put it in an August story, there are now more places in the U.S. to buy a mattress than there are to buy a Big Mac. So, what's a mattress manufacturer to do?Gordon's answer is finding an underserved market. He's the chief marketing officer for Parks Health Products, which sells the Kalmia sleep system. The flashy name fits in with the market's current trend setters: Leesa, Nectar, Keesta, Lull. But unlike the online beds, Gordon said, the Kalmia speaks to buyers who need features typically found only in hospital beds."No one really wants to sleep in a hospital bed," said Richard Schweitzer, who sells the Kalmia in his St. Petersburg store. "There's nothing nice about it — kind of feels like you're at the end of your life just laying in one of those things." Schweitzer owns Affinity Home Medical Equipment, which is next to the Publix in Disston Plaza on 49th Street N. His industry has had major downturns of its own. Cuts and changes to Medicaid and the insurance industry have made it so that the payouts Schweitzer once relied upon are more of a rarity.Now, he acts like a retail shop, not a warehouse moving supplies. He started selling the new beds about a year ago after seeing them at a trade show."They've been a good fit," he sad. "I've got other friends in the industry and they’ve been doing well with it, too."It's easy to argue the bed-in-a-box craze has mainly served millennials — a savvy online shopper who is more likely to look for a cheap and simple alternative to a Saturday at the mattress store. Especially if they're likely to move and don't want to worry about having to sacrifice or transport a $1,000 mattress should they switch cities for a new job.Some king beds on Amazon are under $100, though the nicer ones are closer to a grand. Kalmia full system — which includes the mattress and the machinery that adjusts it — likely outpaces them all in price with the average nearly $2,000 and the large souped-up versions at more than $6,000. "We're not trying to be the cheapest bed," Gordon said. "It's more about the needs." Aging consumers with back problems or mobility issues don't want to make their own home feel like a hospital or nursing home. Schweitzer said he has had customers who were using lift chairs to sleep in every night because they refused to put a hospital bed in their home before switching to the Kalmia.Parks Health — a division of massive mattress manufacturer Hickory Springs in North Carolina — also sells on non-adjustable version of the therapeutic mattress. Hickory Springs has been selling mattresses and bed parts for 75 years. But targeting an aging population is still a new venture. It's the zig to a hyper-competitive industry's zag. An idea, Gordon said, that was birthed by the fact that some 35 million people in the U.S. are already over the age of 65. By 2030, experts predict that number will double.For now, the company is selling the adjustable beds in supply stores and independent retailers, not traditional mattress stores. Even Schweitzer admits those stores can feel like being on a used-car lot with an eager salesman. But that doesn't mean physical retail stores are on their way out.Casper, the leading online disruptor, plans to open 200 brick-and-mortar shops over the next three years. Two are already open in Florida in West Palm Beach and Aventura. A lot of shoppers still want to test a big investment before they buy — even with the money-back guarantees the online shops offer."I wanted to see it, feel it, touch it," said Meaza Stewart-Morrison, 36, who recently bought two California king mattresses for her new Lutz home's bedroom and guest room.She looked online before deciding she felt more comfortable heading to a store to test her options. After Sam's Club didn't have what she wanted in stock, she went to Mattress Firm. She found the same beds there, but $300 more.She said she was able to get them to match the discount store's price — but then came the headache of organizing the delivery date. It took at least two attempts to get it right. "If I got the ones online," she said, "it probably would have been a lot easier to get them on time."Contact Sara DiNatale at [email protected] Follow @sara_dinatale.