Height adjustable side table

[140108654P9E]

Hello, i was designing a height adjustable side table and I came across this table that uses a pneumatic cylinder for smooth height adjusting without the usage of any hand levers or push buttons. https://www.bdiusa.com/products/serif-1045-lift-top-laptop-stand-end-table

I wanted to know how the cylinder is connected without any compressor or valves? 

[hamid.sh.]

I just searched and it seems there are some products available for just this purpose. Check here for example. I see they offer STEP file, so it might help understanding the mechanism and perhaps you can include one in your design.