Simmons Curv 4-inch Gel Memory Foam Mattress Topper - Twin Features the latest in sleep technology; memory foam infused with cool and supportive gel. Open cell memory foam enhanced with Gel creates more airflow for a more comfortable sleeping temperature and prevents excessive heat build up. Topper is reversible for an ideal sleep experience. Place sculpted side down for a more firm sleeping surface. Place sculpted side up for a softer, more therapeutic sleeping surface. Open nature of textured side provides improved air flow. Memory Foam Made in the USA Twin measures 38" x 74" x 4" - Foam Density 3.5lb