The BPK-HD back pack , enables the PAPR to be worn on the BPK-HD backpack. This configuration allows the PAPR to be worn on the wearer's back rather than on a belt at the waist. The BPK-HD is optimized for Adflo and welding application, but may be used for selected additonal 3M PAPR e.g. TR-series and heavy duty industry.The BPK-HD back pack , enables the PAPR to be worn on the BPK-HD backpack. This configuration allows the PAPR to be worn on the wearer's back rather than on a belt at the waist. The BPK-HD is optimized for Adflo and welding application, but may be used for selected additonal 3M PAPR e.g. TR-series and heavy duty industry. This configuration may also enable the PAPR to be worn when a worker already wears other equipment around their waist. For customers in industries who need to have a heavy duty, optimized for welding PAPR backpack, the backpack delivers a robust, ergonomically designed, comfortable backpack that can fit a range of body sizes.