[Fits Multiple Ryobi Cordless String Trimmer Models] This replacement string trimmer spool is compatible with Ryobi ONE+ cordless string trimmer models: 18V, 24V, 40V. [Auto Spool Feed] The easy-to-use Ryobi weed eater replacement spool automatically feeds into the trimmer by centrifugal force, reducing tedious sorting and manual replacement of trimmer spools during work. High mowing efficiency:. Soft, flexible weed line for Ryobi replacement string trimmers allows the line to stretch and cushion against hard surfaces and increases cutting efficiency by 50%, allowing you to cut more than weeds per spool. [Package includes 6 Ryobi cords, 1 spool cap. [If you want the automatic feeding to work better, the recommended solution is to apply powder to the coil, which will provide a small amount of lubricant.