The TR-655 back pack adapter, enables the TR-600 series PAPR to be worn on the BPK-01 backpack. This configuration allows the TR-600 series PAPR to be worn on the wearer's back rather than on a belt at the waist. The TR 655 back pack adapter enables the TR 600 series PAPR to be mounted on the BPK 01 backpack. This configuration allows the TR 600 series PAPR to be worn on the wearer's back rather than on a belt at the waist. Workers may find the PAPR more comfortable or convenient to wear when mounted on the backpack. This configuration may also enable the PAPR to be worn when a worker already wears other equipment around their waist.