Feature●Trimmer Replacement Head Material: Aluminum alloy, matte surface●Applicable Stud Size: Grass trimmer line head spool maximum screw hole 17mm M17 with two screw washers 10mm M10 and 8mm M8●Tightening Method: Tighten counterclockwise, loosen clockwise●Number of slots for string mowing ropes: 8 slots. Can meet a variety of ways to load the strimmer line●Suitable diameter size: Most common nylon trimmer cord, such as diameter 1.6mm, 2.4mm, 3mm, up to 5mm. Suitable for round, square, twist, zigzag and star shapes string wireDescription