Product description Material: ABS Quantity: 8-piece set (6 Spool + 2 Cap), 10 piece set (8 Spool + 2 Cap) Package content: 1 set of lawn mower accessories 1.ABS Material - The edger replacement string spool line were made of premium quality raw material, ABS spool sturdy enough, nylon line string flexible, strong enough for long working life. 2.COMPATIBLE WITH Ryobi One+ STRING TRIMMER - 18V, 24V,40V. Spool compatible with Ryobi One+ original model part AC14RL3A and Cap compatible with 522994001, 3411546-7G, AC14HCA. 3.USE PRECAUTIONS - Strong centrifugal force and cutting fast during using, recommend to wear eye protection and long pants to avoid unnecessary injury. And this cordless weed eater parts refill is only suitable for tender weed grass. Strong weeds will been recommended to use blades to trim. 4.SAVE WORKING TIME-Easy to use and install pre-wound Tool-less installment, pops in and out of trimmer for ease of use,long lasting saves you time and energy. 5.Automatic system Easy 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 makes the tedious work of hand-wound spools easier. The grass trimmer does not block when mowing.