E2608, E2618, E2630, E2632, E2638, E2660 series have IP65 enclosures, meaning they are dust tight and exposure to water jets does not harm the detector. E2610 and E2611 series have IP20 enclosures, meaning they are suitable for indoor use. E2613 and E2615 have the option for IP20 or IP65, depending on application.E2648 and E2658 have IP66 enclosures, meaning they are dust tight and exposure to powerful water jets does not harm the detector.