Spree Sports SmartCap Accessory for Heart Rate Monitor Used with Spree Fitness Monitor POD (sold separately), the Smart Cap gives you the most accurate heart rate, body temperature, movement & calorie count 100% Polyester lightweight fabric, adjustable, features reflective rim, ultra-wicking sweatband, provides protection from the sun with UPF 30 Perfect for running, walking, hiking or any outdoor activity Hand wash recommended