Warranty Parallax warrants its products against defects in materials and workmanship for a period of 90 days. If you discover a defect, Parallax will, at its option, repair, replace, or refund the purchase price. Simply call for a Return Merchandise Authorization (RMA) number, write the number on the outside of the box and send it back to Parallax. Please include your name, telephone number, shipping address, and a description of the problem.