FOUR-SEASON COMFORT & SUPPORT A merino wool top layer added to Superfeets most popular insole, the Superfeet GREEN, so you can enjoy Superfeet’s legendary support with all-season comfort. Superfeet\'s firm, contoured shape provides comfort soft insoles cannot achieve. Insoles are like mattresses. A good mattress is made of firm, supportive materials. A bad mattress is soft and unsupportive. Same thing with insoles. When you stand on a Superfeet Premium Insole, you can feel the firmly supportive shape and materials. It\'s not soft and mushy like other brands…because although Soft non-supportive insoles feel good when you first put them in your shoes, in the long run your foot problems don\'t disappear. Support the Foot. Align the Body. Wearing soft insoles is like running in the soft, dry sand at the beach. Initially it feels good, but you quickly grow tired, waste energy, and begin to feel the stress on your knees and back. Wearing Superfeet Premium insoles is like running on firmer, wet sand. It\'s still comfortable, but your feet feel more balanced and stable, and it\'s certainly more productive and enjoyable from a performance point of view.