【Compatibility】: Compatible with Ryobi One + AC14RL3A. Suitable for multiple Ryobi cordless trimmer models: 18V, 24V, 40V. 【Premium Material】: The replacement trimmer spool line is made of high quality ABS. Not easy to break, supports fast cutting and longer service life. 【Convenience and High Efficiency】: Flexible and strong cord for trimming. 【Auto-Feed Replacement Spool】: Compatible with Ryobi trimmer and uses centrifugal force to feed the trimmer line as needed. 【Package Includes】: 8 packs of trimmer replacement spools and 2 packs of replacement cap covers are packed in one package for you. Spool Diameter: φ56*25mm and straw rope: 3.3M*φ1.65mm replacement spool. Material: ABS and polyamide nylon Three Sizes to Choose Step 1 Stop the engine and brake the cap. Step 2 Replace the spool into the trimmer head. Step 3 Align the retainer with the ground outside the head. Step 4 Cover the trimmer cap. Unplug the tool before changing, installing, or removing accessories. Choking hazard,