An impression of your teeth will be made by you at home with our easy-to-use system. You mail these back to us in the postage paid envelope we provide. Our lab technicians then make your DURABRITE™ Custom Fitted Teeth Whitening Trays from the impressions of your teeth and return these to you, usually within 24 hours. You then apply our Hi-Intensity™ Teeth Whitening Gel inside the DURABRITE™ Custom Fitted Teeth Whitening Trays and place them over your teeth. You may wear the DURABRITE™ Custom Fitted Teeth Whitening Trays from 30 minutes to 4 hours per day. Most people see dramatic results after only a few hours of bleaching time.