There is a small oil resivor next to the electric motor(towards the bottom of the screen) Then you have a small 12v winch motor with a small gear pump in the front. And right next to that you have a small 1-1/2" bore hydraulic cylinder. it is all ported internally and has load checks in both directions to stop the bed from drifting down. the unit is clean and easy to install.
I can tell you this, I have dumped around 1200lbs with mine and it had no problem lifting that. I can also say that right around 900lbs in the bed and you have no rear suspension.