WoCase Pendant Necklace (Classic Style) for Fitbit One (Best Gift for Fitbit One User) Activity and Sleep Tracker Wristband Band Bracelet (One Size, Fits Most Wrist) Best pendant (patent pending) for Fitbit One activity and sleep tracker. Lost-proof Design and Stylish. A new way to wear your One and personalize your One to match your daily style with these brand new color choices. Perfect fit to your One tracker and comfortable wearing experience. 30 day money-back guarantee.