Compatible with Ryobi Cordless Multiple String Trimmer ModelsThis trimmer replacement spool is compatible with Ryobi ONEand: 18V, 24V, 40V cordless trimmer models. Automatic Feed SpoolWeed wacker string replacements for Ryobi weed eater is easy to use, automatically feeds the trimmer by centrifugal force, reducing the hassle of manually sorting out the replacement trimmer line spool during work. Abrasion ResistantTrimmer string replacements for Ryobi weed eater is constructed with upgraded nylon polyamide material that has a tensile strength of over 100 pounds and is 30 percent more durable than other brands for lasting longer life. Cutting EfficiencyThe weeding rope for weed whacker replacements for Ryobi is soft and flexible, allowing the line to stretch and cushion upon impact with hard surfaces, and increase cutting efficiency by 50 percent , making each reel cut more weeds. Professional SellerWe have an excellent service team after-sales and product quality guarantee. Package contains 6 strings for Ryobi, 1 spool cap. If you want the auto feed to work better, the recommended solution is to apply powder to the spool, which will provide a little quantity of lubricant.