Serta Mattress is the No. 1 advertised bedding brand in the United States, with its award-winning Serta Counting Sheep commercials. The company is also the No. 2 bedding manufacturer in the United States, with regards to annual sales volume. Serta was established in 1931 at the height of the Great Depression. At that time 13 independent mattress manufacturers joined together to form Serta. The company, which was originally called Guardian Knight and then Sleep Products, manufactures a variety of mattresses under the Perfect Sleeper and Perfect Night brands. Serta s Perfect Sleeper mattresses feature open-flame resistant technology, advanced comfort quilting, continuous support innersprings, foam encasements and the StabL-Base Triple Beam Foundation. The Perfect Night mattresses features FreeFlex innersprings, foam encasements, FireBlocker systems and quad-beam box springs. Serta s facility in Whitsett, N.C., is one of several company locations throughout the United States.