Any time you have problems, please let us know. We want to provide the best service possible. If any item is unsatisfactory or does not meet your expectations, return it to us for replacement, credit, or refund. Just tell us what you prefer. Biofeedback equipment can be returned either to the manufacturer, Silva Sensor Systems, or you can send it to us and we will take it to Sensor and get it repaired for you. If you need more information please call Silva at 1-800-545-6463