Specifically compatible with Spear & Jackson S4528ET grass trimmers for optimal cutting performance and compatibility. Durable line provides clean, precise cuts through grass and weeds with minimal line breakage. Easy to install and replace, easy to replace no special tools required for spool changes during trimming sessions. Ideal for regular garden maintenance; maintains smooth operation and reduces wear on your trimmer. Includes 4x trimmer spools for quick replacement, saving time and ensuring uninterrupted lawn care., Manufacturer: Briny River