Made from the drive gear of a Whirlpool washing machine. I just cut a hole big enough to reach the retainer collets with a magnetized screwdriver. The spring retainers perfectly fit inside one end, the C-clamp nubbin fits the other almost as well. The other part is the agitator pinion from the same washing machine.
It isn't suitable for installation, but I only needed to dismantle the head anyhow.