PVC material single bladder safety buoy. Supplied 17m of orange thread + "Fox" flag, available in round or torpédo. The leads pocket has to be hanged on the edge of your double bladder buoy. When you place a 2kg weight inside, the buoy rise up like a beacon for a better visibility and safety on water. This beacon mode is usefull for spotting a roc or a drift hunting area. To get back the buoy to single torpédo, just stuff the 2kg weight in the internai bladder of the buoy.