[Ryan Curry]

Just from looking at it, I can guess (not certain) that there is a simple rack & pinion inside. The rack is pnuematically driven inside the cylinder, and the pinion is attached to the output thus making linear into rotary motion.

For this year, we are limited to 90 deg of rotation, but at our pnuematic workshop we were told there are limiting screws taht can be adjusted to let it turn up to 320 deg under internal limits only.