Combined Hepa and Carbon Filter. The Hepa H13-grade filter captures ultra-fine dust, allergens, and 99.97% of particles as small as 0.3 microns. We recommend replacing your filter every 12 months. Over time, filters can get clogged with pollutants, reducing air flow. Using Dyson Genuine replacement filters ensures a sealed filtration system, Hepa standard and proper functioning of the machine. Compatible with Dyson models: PH04, PH03, PH03, PH3A, PH02, PH01, HP10, HP07, HP06, HP09, HP04, HP4A, TP10, TP07, TP09, TP06, TP04, TP4A, TP7A, DP04, PC1, and HP1. Percentage varies.