This connector is used to attach the exhaust hose to the back of the AC unit! The inside diameter of this connector is 5-7/8 inches. This part does NOT come with installation instructions. This original Delonghi Air Conditioner AC Appliance Connector originally shipped with the following Delonghi devices: PACEM370WH, PACEM365WH, PACEM360WH This is a true Delonghi part! This item is NEW! Don't see your model number? Send us a message as we are happy to help!