Product Details ONA PRO is new and exciting! These are professional grade products. The first product in this series is ONA PRO Gel. Constantly striving to improve their odor neutralizing products, ONA has developed a formulation that takes odor control to a new level. ONA PRO Gel is as close to odorless as they have ever come. Although it has a slight scent when sniffed in the container, the final result when working on powerful, noxious odors is simply a clean, fresh smell—period. It leaves nothing behind to indicate that any odors were present. ONA PRO Gel is the best ONA has ever done, and it is all you will ever need. No scrubbers, no filters, nothing—just ONA PRO. ONA offers a MONEY BACK GUARANTEE if you are not satisfied with the results. We have tested ONA PRO in the most malodorous conditions, and have found that it performs remarkably every time.