This listing is for a replacement bump knob that fits 40v Cordless GreenWorks string trimmers, such as the GreenWorks ST40L412 (see 5th photo in listing).

I couldn't find this part for sale by itself, and I didn't want to buy a whole new stringer head each time I needed this part. For me the original bump knob wears out after a few months of use when maintaining a large lot, so I designed this part and printed it with my 3d Printer.

Note to DIY'ers: If you want to print this same design using your own 3d Printer and PETG filament, goto Thingiverse and search, "GreenWorks 40V String Trimmer Bump Knob Replacement Weed Wacker" and you'll find all the info you need to print it yourself. Of course if you want one all printed and ready to go, then buy my listing here.

It's printed with strong, durable PETG filament and is nearly solid filament, so it should last twice as long or longer than the original bump knob (which is mostly hollow). Note: It's about 5mm taller than the OEM part so it will have a slightly higher profile, which means a tad less ground clearance but should also help it last longer.

Listing includes:

- One 3d printed PETG GreenWorks Bump knob

Not included, but shown in listing photos: OEM trimmer head and OEM bump knob