Mirror Ducts guarantees to provide you with the most professional, top of the line service. If you are not happy with our service, we will offer you a full refund. Or, offer to clean your entire system again free of charge. We also guarantee to show you before and after photos of your duct system at the end of each job, with the time and location the photos were taken. Technicians will wear shoe covers in your home, and provide you with a full invoice once the job is completed.