Good luck purchasing this and installing it, especially if you are trying to upgrade a system already in place. It came with no clear directions, the software is a nightmare to download, and after 3 full days of trying to install it, it still isn't working. The exit button lets you out, but we cannot get it to connect from the pinpad to the door magnet to let you in with the correct code. The software will not help with programming, as it continuously tells me I have the wrong serial number, desSee full review