Those are just Pnumatic cylinders. Look up Bimba or SMC cylinders to get an understanding of how they work. The piece in the other hole is called an air muffler and does exactly that quite the air noise down. It does provide some resistance but not much.
Well after searching and finding a great deal on a Full Rise Scissor lift and using it a lot for home use anyways. I came to the realization that a MidRise scissor lift would have worked just fine for everything I have used my lift for.