Compatible with Ryobi Cordless Multiple Cordless Trimmer ModelsThis trimmer replacement spool is compatible with Ryobi ONE+: 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% more durable than other brands for a longer lifespan . Cutting EfficiencyThe weeding rope for weed whacker replacements for Ryobi is soft and flexible, which allows the line to stretch and cushion upon impact with hard surfaces, and increase the cutting efficiency. 50% cutting efficiency, allowing each reel to cut more weeds.