The strap is made of a soft fabric for more comfort the size is adjustable to your body so it stays secure during your activity once its paired with your compatible device the first time it will automatically recognize it each time and it39s optimized for use in crowded areas like the gym and road races so it wont pick up any signals but your own taking care of it is a snap the plastic heart rate module is removable from the strap so you can wash the strap as often as needed