The little part that is your scooter's "accelerator." Here is the speed pot knob for the Golden Technologies Companion I (GC221) and Companion II (GC321, GC421) mobility scooters.
At Monster Scooter Part's low price, you may as well get an extra one for a spare. So now there is no reason to fret over a lost knob. Monster Scooter Parts is always your very best source for speed pot knobs.