The backpack adapter allows users to locate cartridges and filters out of the work zone, by placing them on the user’s back. The BP1002 is easily adaptable to all North Full Face piece and Half Mask air-purifying respirators, simply by attaching it to the face piece cartridge connectors. It is ideal for tight or highly heated work places such as those encountered in welding operations. Think of it as an extension cord for your cartridges. NOTE: Face piece and Cartridges sold separately.