CR-7: 10.8mm m3 hand nut extension

thingiverse

People who prefer using a metal hand grip say it's more powerful, although finding one locally is difficult. The unconventional shape also makes it clear which way to turn the object, since you see all of it on its side and don't have to turn the thing itself just to tell what you're doing. A quick glance at this component shows that the diameter measures 10 point eight millimeters.