Brattle experts estimated damages associated with an infringement claim regarding a target device design in a hand-held remote thermometer used by heating and cooling system engineers and operators. Our team used the warranty cards submitted by purchasers of the competing devices to determine the value of the patent. The cards provided the identity and contact information necessary to conduct a telephone survey of buyers. The survey instrument was designed to collect information on the price paid, the type of device purchased, and the importance of a set of device features. State-of-the-art statistical analyses were then used to determine the plaintiff’s lost sales. The jury adopted Brattle’s damage estimate.