Versaflo™ Filter cover. For TR-6500 series cartridges. The filter cover for use with the TR-6510N, TR-6530N and TR-6590N cartridges. Recommends the use of the filter cover to help protect cartridges from damage. It is used to hold the TR-6600 prefilter or TR-662 spark arrestor in place. Easy to use. Helps protect cartridge from physical damage. Enables use of prefilters and/or spark arrestors. Enables PAPR to be worn through decontamination showers or rain.