Fitbit Charge Fastener Ring, HWHMH 12pcs Silicon Fastener Ring with 3pcs Clasp for Fitbit Charge Wristband - Fix the Clasp Fall Off Problem - (Note: Tracker or Wristband Not Included) 12pcs Black Fitbit Charge Fastener Ring. Includes 3pcs Clasp: Black,Slate,Navy. Designed specially for fitbit charge to protect the clasp loose and band fall off. This simple insurance will keep your Fitbit safe. Light weight and more flexible. Slide the ring over the clasp when you put on your wristband, simple as that. Note: for Fitbit Charge Only. Not fit other activity trackers or wristbands. Tracker or Wristband NOT included.