The streamer leader is built especially for throwing streamers for bass, trout, or anything in between. Hand tied by us at BLC HQ. Made with the highest quality flourocarbon. Swivel in the middle doesn&';t effect casting or sink rate. This gives a better presentation by allowing the fly to roll in the water column and not spin your leader when casting big flies. 8- Small Swivel- For small flies and the most weary fish 12- Small Swivel- For fish that are tippet shy (Our top trout choice) 15- Small Swivel- For nearly any fly and for fishing in a close combat environment. (Our choice for Bass) 20-Medium Swivel- For the brutes. Big bass, Gar, White bass, etc. When fopr when you need to get after it. 25-Medium Swivel- When you need to give 'em nothin.