Our Mattress 1st Collection is built around VertiCoil® Premier™ innerspring units that provide a consistent, supportive mattress core with higher-than-average coil counts. This makes our Mattress 1st Collection more responsive than the average mattress, resulting in a better quality of sleep. Layers of foam and fiber are used with the innersprings to create various levels of softness throughout the Mattress 1st Collection. You can find just the right level of comfort.