Nylon trimmer line is replacement part for brush cutter/grass trimmer/grass eater/whipper snipper.

But it also can be used for some other place.

Like the following picture, it’s hard to image what’s it used for. yes, it is used on agriculture machine, one of it’s usage is to rake up Macadamia Nuts.  the lines can be used for similar fields, like a brush sweeper.

brush sweeper