Your choice of available sizes. 10 year limited warranty. Super soft memory foam and fiber. Hypoallergenic. Spot clean only. Transform your traditional mattress into a luxurious refuge of comfort with the SensorPedic Memory Cloud Gel Memory Foam Mattress Topper. This add-on instantly takes your sleep cycle to another level thanks to its innovative hypoallergenic design and soft, memory foam fiber fill. Lengths and widths of available sizes vary, but all toppers measure a generous three inches thick. Size: King.