Carbon Register Vent Air, Odor & Dust Filters 3 Pack 12" x 16" by CFSCategory: Fresh Air Vent AssemblyCarbon Register Vent Air, Odor & Dust Filters 3 Pack 12" x 16" by CFS CFS Activated Carbon Register Vent Filtration - Each package contains 12 vent filters. Has a activated charcoal impregnated in a poly mat to help trap dirt, dust, smoke, pollen sized particles and reduce odor through furnace/AC registers. Keeps dirt & objects from falling into ducts. Can be trimmed to fit standard size vents --- 4" X 12" and under. Why use Register vent filters? • Register vent filters are made of a self-charging electrostatic material attracts dust, smoke, pollen and other pollutants in your vent register system. • Use in any room of your home or RV. • When air flows through the filter, dirt, dust, smoke, and pollen sized particles are trapped. Filtered air then passes back into your house. • Naturally reduces odors through your home. • Keeps dirt and objects from falling into ducts. • Vent filters are designed to provide filtered air in your home.