Single temperature model heats the bed at a steady rate through the night. Simple On/Off switch with lighted toggle makes it easy to see when unit is On or Off. No more wearing heavy socks to bed! The perfect solution for people with poor circulation or cold feet! 18" X 36" size works two ways - 1. Perfect fit for one side of the bed, when one of you wants more heat than the other 2. Lay across the bottom of the bed to share, for warm feet and legs, Size/Application: 18 by 36 inches. Fits under sheet on mattress pad for feet and legs. Features: Efficient warmth rises through sleeping space. Costs less to operate than electric blanket.