T25 Weed Wacker String Trimmer Head For Husqvarna Husky 966674401 537338306 Special material , high quality plastic and metal ,and 30% nylon Easy to reload spool with the cap, eliminating the need to turn the trimmer upside down to reload the line Two key slots to lock the trimmer line Speed is fast, up to 13300rpm (max) Tap Head for quick and easy loading