Silver Streak Razor Trimmer Line features 5 cutting edges, providing for a cleaner cut with greater uniformity in appearance. This trimmer line is recommended for heavy-duty usage, allowing for the trimming of coarse grass and weeds. The razor-sharp cutting edges deliver a clean and shear cut with less browning of grass blade tips. Stens has added extra durability to its Razor trimmer line with a robust coextruded design, which features a durable and flexible inner core for strength surrounded by a tough, long-wearing outer shell. Co-extruded line delivers a longer service life with decreased breakage, fraying and line welding. You’ll experience significantly less breakage with co-extruded line when coming into contact with hardscape surfaces. With its quicker cutting, Razor trimmer line offers better fuel efficiency, reduced noise levels and less vibration from the trimmer. Razor trimmer line delivers the most professional results for discerning homeowners and lawn-care services.