Oregon 20-108 Platinum Gatorline 1-Pound Donut String Trimmer Line 0.155-Inch Gauge Compatible with most trimmer head systems High resistance to abraision, breakage and welding Resistant to cracking and breaking Less resistance, engine drag, vibration and noise compared with traditional round nylon lines High resistance to abrasion and breakage. Flexible core provides outstanding durability. Less engine drag, vibration, and noise. Engineered to resist welding up to 498 F. Outer layer prevents welding. User friendly donut  fewer tangles. High strength inner core resists breaking. Long-life, excellent strength. Fits all standard trimmer heads. User-friendly donut, limits tangles. Fits all standard trimmer heads. Effective in all cutting conditions.