[Compatible Models] ART 30-36 , ART 30, ART 27 and ART 24. Spools Product Number: F016800351. [Autofeed System Replacement Spool] trimmer replacement spool is compatible with the lawn mower, and can use centrifugal force to transport the trimming thread as needed, effectively reducing the work of manually winding the spool. [High efficiency] The spool can be stretched and cushioned under the impact of a hard surface, and aerodynamic shape allows more effective cutting and reducing resistance, making more efficient. [High ] The flexible and strong nylon spool is made of high- ABS material, which can easily pass through grass and weeds. spool, not easy to break, supports fast cutting. [Packing list] 4 x F016800351 replacement trimmer spool. Spool specifications: length: 6.1 m/20 ft, diameter: 1.65 mm/0.065 inches. Color: black, gray Material: Nylon, ABS Contents: 4pcs String Trimmer Replacement Spool Only the above content, other are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.