Ecolink Intelligent Technology DWZWAVE2-ECO-2 Z-Wave Battery Operated with Magnets Door & Window Sensor, White & Brown Features industry leading Rare Earth Magnets that allow for up to a 5/8 inch gap , which makes it perfect for double hung or commercial windows. Easy installation by simply pulling the battery tab to begin the learning process. Both white and brown plastic casing included to match any dcor. Tamper sensing premium design outlasts the competition and boasts a battery life of up to 5 years. Works with most brands of Z-wave home security hubs.