We acquired the units in a state surplus sale. We don’t know the prior usage history. 30 days return right for the US buyers. I always work with my customers to resolve any problem. For all others, there will be extra. Regardless of the origin of the equipment, documentation provided or identification appearing upon the equipment, the equipment described and offered here is in no way certified for, recommended for, or offered for any specific use. The sale of this item may be subject to regulation by the U. Food and Drug Administration and state and local regulatory agencies. 1841 W Carriage House Dr, Baton Rouge, LA 70815.