Durable Material: Lawnmower accessories with durable plastic knobs, aluminum head with aluminum left nut (M10 x 1.25), long-lasting use. Efficient: The replacement spool simplifies the tedious work of manual threading. It is very suitable for cutting grass and can be optimized for the best, precise cutting effect and greater cutting efficiency. Dimensions: The nylon head measures 12 x 7.5 cm, the line length is 2 m, the diameter is 2.4 mm, and the nut size is M10 x 1.25, optimized for extremely high performance. Strong Compatibility: The self-contained spools of these nylon heads fit most types of lawnmowers and are highly compatible.