Marine: Boating, Sailing, PWC, GPS and Navigation - knowledge on simple dc motors

I have a electrical motivated cylinder. The cylinder has loads both going in and coming out.

It seems to be powered with a simple dc motor. It has two wires: red and black.

With two wire motors, I thought you simply reversed polarity to get it to go in and come out. Is this true in my case?

With three wire motors, one is common (black wire), and you simply switch the other two terminals with "in" wire, and "out" wire (putting 12v on one or the other).

It is possible that reversing the polarity would work, or the motor may be grounded through it's case. If that is so, then only one wire would be energized at a time, with the motor shell being attached to metal which eventually leads back to the battery.

You need to do some research with a volt / ohm meter before applying power.

It's also possible that internal switches reverse the motor when the cylinder gets to the end of its travels.

What is the purpose of this device? Who makes it? Is there a model number?