Bradychan Magnetic Clasp Silicone Clip Strap for Fitbit Flex Wristband Bracelet Activity Tracker Monitor 2Pcs Set Replacement Clasp clip strap set for Fitbit flex Perfect and stylish way to secure your activity and sleep tracker. The magnet inside the clasp can firmly adsorb your Fitbit flex. You can attach it to your cloths, shoes. Made with Silicon. Prevent skin irritation.