The Essentials Sudley Firm mattress is a great option for back sleepers, as its coil system provides a supportive, firm feel combined with a gel foam layer for a hint of plushness and added comfort. With 525 coils, you can expect a supportive, sleep-on-top-of-the-bed feeling every night. The Essentials Sudley Firm is an essential for a great night's sleep at an affordable price. PRESSURE RELIEF: The gel foam comfort layer is uniquely designed to relieve pressure points and provide a hint of plushness for increased comfort while you sleep.