Compatible with Multiple Ryobi Cordless Trimmers ModelsThis line string trimmer replacement spool is compatible with Ryobi ONE+ Cordless Trimmer Models: 18V, 24V, 40V. Automatic Feed SpoolEventronic weed wacker string for Ryobi weed eater is easy to use , automatically feeds the trimmer by centrifugal force, reducing the tediousness of manually sorting out the replacement trimmer line spool during work. Abrasion ResistantEventronic trimmer string for Ryobi weed eater is constructed with an upgraded nylon polyamide material that has a tensile strength of over 100 lbs and which is 30% more durable than other brands for longer life. Efficient Cutting Eventronic weed eater string for Ryobi weed wacker is pliable and flexible, allowing for the line to stretch and cushion on impact with hard surfaces, and increasing cutting efficiency by 50%, making each spool to cut more weeds. Professional SellerAs a professional brand, we have an excellent after-sales service team and and product quality warranty. Package contains 6 ryobi strings for Ryobi, 1 spool cap. Product Description Easy to Install You have to put the spool in the correct orientation, and close the cap to secure it. The spools work fine once you get that right. Auto Feed It automatically feeds when needed which achieved by centrifugal force, so please note that auto feed must be in high gear. Pre-loaded Spools Manual winding usually cause uneven surface, it make the weed trimmer difficult to work, the pre-installed spool is more convenient, protects your Ryobi Cordless Trimmers and prolongs the life of your machine.