Xiemin Silicon Fastener Pack Replacement Clasp Clip Cover Strap Wristband Bands for Fitbit Flex Activity and Sleep Tracker Multiple Color Set black+blue+cyan, 3 pcs Replacement Clasp 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.