Serta Grandeur 12-Inch Memory Foam Mattress With 20-Year Warranty, Twin 12-inch memory foam mattress with exclusive 3-layer construction Three layers of premium foam; top comfort layer: 1-inch of extra-soft memory foam; middle support layer 2-1/2-inch of memory foam treated with SureFresh for lasting freshness; bottom layer 8-1/2-inch of support foam for stability Relieves painful pressure points and reduces motion transfer so that you can sleep undisturbed; superior breathability for a comfortably cool sleeping temperature After unpacking, allow up to 72 hours for mattress to fully expand; Spot clean only