You must return the product at your own expense, using the carrier of your choice. Return the defective Eligible Products according to the return label on the RMA shipping packaging.If you have received your product with a defect you should write to us through our Contact Form and wait for your case to be assessed. Our 90-Day Limited Warranty covers defects in materials and workmanship, starting from the original date of purchase. If a product is found to be defective within the warranty period, Franklin Sensors will, at its sole discretion, either repair or replace the defective product. To obtain repairs or replacement according to the terms of this warranty, the product should be delivered with proof of Warranty coverage (e.g. Attn: Returns Department. 8. Inspections and Acceptance of Claims. You must report to us any mistake we have made with regard to filling your order within 5 business days of your receipt. How do you prove a manufacturer's fault to resolve a defective product claim?