Drennan Fluorocarbon fly leader is popular for it's ultra low visibility and is favoured by many anglers for its stiffness which can help turnover with those longer fly leaders. Drennan Fluorocarbon is clear in colour and has a refractive index close to that of water which means once submerged it is virtually undetectable to fish increasing fish strikes and catch rates. Like most of Drennan's fly leader this fluorcarbon is supplied on a 50m spool with the spool itself having a unique rotating centre section for quick and easy unspooling of line.Fluorocarbon Fly Leader Material. 50 meter spool. 4lb, 5lb, 6lb, 8lb, 10lb, 12lb.