Choose Your Preferred Loft – The 3.9 in Mid Loft is often preferred by back sleepers, people with narrower-to-average shoulders, softer-mattress users, and those who prefer less pillow height. The 5.1 in High Loft is often preferred by side sleepers, people with broader shoulders or muscular upper bodies, firmer-mattress users, and those who prefer taller, steadier support. Dual-Layer Memory Foam – This pillow features an ergonomic dual-layer foam construction that combines soft cushioning with steady support. The upper layer gently cushions your head to release pressure, while the firm bottom layer delivers targeted neck support to maintain a relaxed position for all-night comfort. Innovative R-Curve Design – The innovative R-shaped curve design of the memory foam pillow core provides a comfortable support for the neck that adapts to your shape and sleeping position throughout the night. Pillow Cover with PCM Technology – The removable, soft-touch cover incorporates phase change material designed to absorb and release heat as surface temperature changes, helping create a more balanced sleep surface. The zip-off cover is machine washable for easy care. Temperature sensation may vary with room conditions and individual preference. Removable & Washable Cover – The zippered pillow cover is easy to remove and machine washable for simple care. (Note: The pillow insert is not washable.) A practical sleep upgrade for your bedroom, guest room, or daily routine.