Telescoping doors are a type of sliding door system that consists of two or more door panels that slide and stack on top of each other to open and close. Just like a telescope! The panels are usually hinged together and slide on tracks that are installed on the top and/or bottom of the door opening. Telescoping doors are commonly used in commercial buildings such as airports, shopping malls, hotels, and hospitals, where there is a need for large openings that can be easily accessed and closed. T...