NU-CALGON 4.25 lb. Odor Neutralizer, White Gel

Bought this from my local HVAC shop and it's so good I came here to make a review. The block itself has a scent and you might think "my whole house is going to smell like this." Wrongo. It gives a very fresh no-scent, like purified air. Similar to what the inside of an empty fridge might smell like. Just cold air smell. It's great.It's currently in one of my returns laying on its side in the duct work. I plan to move it to after the evap coil (there's an image on the box of this configuration) after a few days use.