Makita B-60121 Commercial Grade Automatic Feed String Trimmer Head M8 x 1.25 RH arbor and 3/8" X 24 RH arbor Accepts up to 17 of .080", 12' of .095", 10' of .105" and 9' of .110" trimmer line Trimmer head comes equipped with .095" standard round trimmer line Trimmer head feeds line automatically and can be simultaneously bumped to quickly extend line Dual track spool