This trimmer line is manufactured to the highest possible specification for ultimate performance and longevity! It is situated in a spool that fits inside the trimmers head, spinning at very high revolutions to do the trimming. Through use, the line can wear down or break, so more line must be fed out from the spool. When your existing line has been used up, you need this replacement to get your trimmer back in action. Top Tip: Changing your line at the start of the season makes trimming the garden easier. All trimmer line degrades over time and using new line offers greater flexibility and resilience, which results in less line breakages. The trimmer line is colour coded by thickness and is suitable for ALL makes and models of trimmers from electric to large petrol machines.