| Business | Phone |
| Air Purification Inc 8121 Ebenezer Church Rd, Raleigh 27612 | (919) 783-6161 |
| Tri-Dim Filter Corp Raleigh 27612 | (919) 782-6987 |
| E Z Breathing Enterprises 10 Natalie Dr, Raleigh 27603 | (919) 662-7703 |
| National Air Filters Inc 1109 N New Hope Rd, Raleigh 27610 | (919) 231-8596 |