The Quad-DM™ Ion Generator for In-Duct HVAC units was developed to produce bi-polar ions in the conditioned space of homes and commercial buildings. This system has separated quad ion emitters for superior Bi-Polar ionization. The Quad-DM™ reduces particulate, allergens, smoke, bacteria, viruses and mold spores. This unit is designed to be mounted in the HVAC air handler and installed using its no tools required magnetic mount for quick and easy installation. The Quad-DM™is a good air quality solution for the budget minded consumer.