PK720: 60 Filers HEPA total (54 in package 9024 and 6 in package 9029). PK-721: 60 Filters HEPA total (54 in package 9025 and 6 in package 9029). PK-731: 66 Filters HEPA total (30 in package 9026 and 36 in package 9027). PK-820: 48 Filters HEPA total (24 in package 9026 and 18 in package 9027).