The Zephyr is a device about the size of an attache case which, when hooked up to an ISDN line, can provide high-quality voice transmission from a remote location back to a receiving radio studio. Adam bought one initially so he could do ocassional fill-ins on the Howard Stern show from his house, and at some point Drew also bought one to use when travelling. Now, when either of them is away from the studio, they will usually bring their Zephyr along and set it up in their hotel or other ISDN capable location, so they can still participate in the show.