The AcuRite Lightning Detector provides lightning protection by warning you of cloud-to-ground cloud-to-cloud and intra-cloud lightning strikes within a 25 mile (40 km) range. The lightning monitor notifies you with a loud alarm flashing red LED light and text message on the backlit display when storms or lightning are within range. Pocket-sized with no-slip clip for portability. The detector features enhanced interference rejection capabilities to prevent false lightning detection. Outdoor and indoor operation modes. One-year limited warranty. It s more than accurate it s AcuRite.