Online-only retailer Casper Sleep limits consumers’ sleeping options down to one mattress. Casper launched in 2014 selling a single type of mattress made out of memory and latex foams. The material allows the retailer to ship its mattresses—no matter what size—in a shrink-wrapped UPS box. Prices range from $500 for a twin size to more than $1000 for a king size. Casper offers a 100-night home trial that allows customers to return the mattress for a full refund. Casper expanded its product line in 2015 to include a pillow and sheet set. In June 2015 Casper raised $55 million in Series B round of funding led by investment firm Institutional Venture Partners.