This is the 3M 501 PREFILTER RETAINER that snaps on top of 3M cartridges and used to hold 3M Particulate Filters 5N11 and 5P71/07194(AAD) in place on top of 3M Respirators 5000 Series and 3M Cartridges 6000 Series and 3M Filter Adapter 603.
You will still need to purchase the respirator and the filter and the cartridge.
WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.