A:Answer Hello there - We're glad to offer some insight in finding a telescopic downdraft system. If your current cooktop has a telescopic system already attached to the unit, then unfortunately, you won't be able to replace just the vent itself. If this is the case, then your options include using your current cooktop without the vent system or replacing the cooktop entirely and buying a telescopic downdraft system at the same time. As for raising and lowering the vent, there is a button on top that you'd press to do so (you can see a diagram of this on page 5 of the owner's manual: https://files.bbystatic.com/1HsCGH3M0oInsp0HFgG3rQ%3D%3D/User%2BManual). We hope this is helpful. If you have any further questions, please connect with us and we'd be happy to help out.