Increase the battery run-time and reduce operating costs when using 3M Adflo Powered Air Respirator with 3M Adflo Prefilter, 836010. Our prefilter captures large particles that may otherwise clog the particle filter, reducing operating costs by extending its life. It can also increase battery life efficiency. It comes as a pack of five and must be installed and used according to the user instructions. To increase service life, make it a habit to check your equipment regularly. Pack of 5.