Sundstrom Pre-Filter SR 221 

Protects the SR 510 P100/HE particulate filter against premature clogging of the larger particles while also greatly prolonging cartridge filter life. Suitable for all Sundstrom half masks, full face masks and powered air purifying respirators.

The SR 221 pre-filter is a non-classified filter media designed to capture coarse and larger particles while extending the life of the particulate filter SR 510 and SR 710. The pre-filter is placed in the pre-filter holder which attaches to the particulate filter.