【Compatibility】: Compatible with Ryobi One + AC14RL3A. Suitable for multiple models of Ryobi cordless trimmers: 18V, 24V, 40V. 【Premium Material】: The cutting 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 cutting. 【Replacement Spool for 【Auto Feed】: Compatible with Ryobi trimmer and uses centrifugal force to feed the trimming line as needed. 【Package Includes】: 8 packs of replacement trimmer line spools and 2 packs of replacement trimmer cap covers are packed for you. Spool diameter: φ56*25mm and straw rope: 3.3M*φ1.65mm replacement spool. Material: ABS and polyamide nylon Three sizes for you to choose from Step 1 Stop the motor and brake cap. Step 2 Replace the spool in the head of cutting. Step 3 Align the bracket with the screw on the outside of the head. Step 4 < p>Cover trimmer cap. Unplug the tool before changing, installing or removing accessories.