Trimmer Head / Ryobi 791-153577 B Pack Size:1 RYOBI 153577, RYOBI 791-153577 B LASER 87137, OREGON 55-266 RYOBI 130R, 135R electric trimmers, 700R, 710R, 720R, 740R, 750R, 760R, 765R, 766R, 770R, 920R,970R, CS720R, SS720R, Singer GT2815, GTS2816and GTE2818; Yard Machines Y28 and 2800M Includes trimmer line , For dual line models , For 3/8" shaft diameter