We make specialty bedding for all adjustable mattress types including Split King and Split Flex Top King Sheets like those sold by Sleep Number. Our CinchFit Adjustable Mattress Sheets stay on and do not pop off at the corners. Our Flex Top Sheets with FlexSquare Reinforcement never rip or tear. Our products are hand sewn in Brunswick, Maine. We provide exceptional and personalized service . See our fabulous reviews by clicking our testimonials section at the bottom of the page.