With a hybrid mattress you get the best of both worlds: the traditional supportive feel of springs with the added comfort technology of memory foam. The Serta iSeries Hybrid 100 13.5 firm mattress is no different, combining the company's 886 Pro-Supportâ„¢ Coil System and its sturdy spinal support with multiple layers of support foam and gel memory foam. The Serta iSeries Hybrid 100 reviews show that it's a good mattress for back and stomach sleepers, providing the spinal alignment and pressure point relief necessary to prevent the development of back and shoulder pain. The iSeries 100 firm also rates highly for repositioning, meaning that if you like to switch sleeping positions throughout the night, it's easy and comfortable to do so. If you like an extra firm feel while you sleep-on top of your mattress rather than sinking into it-the Serta 100 mattress keeps you afloat and cool while you sleep. You don't have to take our word for it, though. Try it out in your local Mattress Firm store, or order online and take advantage of our 120-night sleep trial.