The Rocketbox PTO is a shifting transmission designed to send power out to either of two output shafts, independently. PTO stands for "Power Take Off" and is a term commonly used for mechanisms which can switch supplied power from one shaft over to another. On our Rocketbox, one shaft is intended to provide power to a robot drivetrain (aka: Drive Output Shaft) while the second shaft may power separate appendage, arm, winch, or any other mechanism (aka: Mechanism Shaft). Both output shafts cannot be powered at the same time.