4 Way Stretch is the "wear less, do more" base layer that is perfect for any cool or winter activity. The form-fitting acclimate dry polyester fabric provides maximum mobility, enhanced breath-ability and moisture wicking comfort. 4 Way Stretch is ideal for moderate exertion and colder climates. Material: Heavy Weight 4-Way Stretch XG Fabric. 92% Acclimate Dry, 8% Spandex. Moisture Wicking. Breathable & Quick Drying.