This is Stihl's 0000-930-4314 .105 CF3 Trimmer Pro Line. The CF3 Pro Trimmer Line is a durable line, tough enough for virtually all trimming conditions. It is formed using 3-component, tri-extrusion technology and high-quality polyamide components. This ensures strong durability with excellent cutting performance. Best of all, it is compatible with all STIHL nylon line trimmer heads, making the CF3 Pro at home on any landscape trailer or in any garage. This line is great for both homeowners and professionals.