CompatibilityThese replacement trimmer spools are compatible with One+ AC14RL3A. Suitable for grass trimmer models: 18V, 24V, 40V electric thread cutter. . Premium MaterialThe trimmer line spool is made of high-quality ABS material. High quality automatic feed trimmer spool are strong and firm. Not easy to break. The nylon cord supports fast cutting and longer life. . Comfort & EfficiencyThe aerodynamic shape allows the line to deflate on impact with hard surfaces, allowing for less drag for more efficient cuts. The grass cutter spool provides a larger mowing area and reduces damage to the trimmer. . Automatic systemEasy to assemble and use. Compatible with the Ryobi line trimmer and uses centrifugal force to feed the trimmer line as needed. With the Auto System, the spare spool eases the tedious work of manual winding spools. The grass trimmer does not block when mowing. . Packing List6 pieces of replacement threads are in a packet for you. The replacement cord is 3.3m in length and 1.65mm in diameter. They can be used for a long time. .