The Austin Air HealthMate HM400 Filter is constructed using a true medical High Efficiency Particulate Arresting (HEPA) filter surrounded by a carbon/zeolite mixture capable of removing the tiniest of particles and absorbing odors and gases. The Austin Air HealthMate HM400 Filter uses the HEPA to remove up to 99.97 percent of all particles down to 0.3 microns in size and 95 percent down to .1 micron
This is a complete filter set. A Prefilter, HEPA replacement filter and 15 lbs Activated charcoal for the larger standard size Healthmate Plus.Sometimes referred to by internal Austin part# HM450. Fits all standard models built after August 1995.