The Backpack adapter allows users to locate cartridges and filters out of the work zone, by placing them on the users back. The Backpack adapter is easily fitted to all North full facepiece and half mask air-purifying respirators, simply by attaching it to the facepiece cartridge connectors. It is ideal for tight or highly heated workplaces such as those encounters in welding operations. Think of it as an extension cord for your respirators.