Magna drive suspension

[genopower]

I'm confused. I have an S3 with the adjustable suspension. I thought it was magna drive. Recently I got a suspension failure light and the dealer replaced the two back struts. He said they were connected to an air line. So this is where I get confused. I thought the struts were electronically controlled by energizing an electromagnetic that changed the viscosity of the fluid in the shocks. If so, then why the air line to the struts? Anyone know? Thanks. Chuck.