"Nylon external material double bladder safety buoy // Interchangeable internal PVC bladder. Supplied 17m of orange thread + “Fox” flag, available in round or torpedo. 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 torpedo, just stuff the 2kg weight in the internal bladder of the buoy. By the way, It gives a better balance on the water. Pocket not included."