Easily customize your SmartBand to suit your style with the Sony SmartBand Wrist Straps. Each wrist strap is made from silicone, providing a comfortable fit as you go about your day, and comes in three different colors, including Black, Blue, and Orange. Now, you can quickly and easily match your wristband to your outfit or your mood! Plus, it"s easy to swap out the color of your wristband! Simply move the metal fastener and the core unit from one wrist strap to another! (metal fastener and core unit not included) Wristbands come in a size small that measure approximately 8.4 inches in length.