I created this replacement part for my electric grass trimmer. It fixes trimmer spool and if pushed it allows release of synthetic rope.
Better print it using hit resistive material like ABS, HIPS, so on to make it more durable.
This screw button has 10.4 mm hole for 10mm shaft of trimmer and holds M13 screw. Original button also has 17.5mm (size is updated) steel cover. The button is enforced a little bit since printed parts are usually less durable than extruded one under pressure.
Note: version 2 updates diameter of steel cover 17->17.5mm to better match its real size.