The print mark contrast sensor DK21-9,5/9S50/110/124 is a high-precision optical sensor element for reliable detection of print marks on moving or stationary surfaces in industrial automation. With a range of 9.5 mm and an extremely short response time of 30 µs, it is ideally suited for applications with high speeds and dynamic processes. The integrated Dynamic Teach-In function enables automatic switching threshold adjustment with a single button press, making commissioning and adaptation to different marks quick, easy, and error-free. The RGB illumination with three emitter colors (green, red, blue) and a rectangular light spot projection ensures optimal contrast differentiation, regardless of the mark's color, size, or position. The optics are interchangeable by 90°, allowing flexible mounting on various system configurations. The push-pull output ensures secure signal transmission, while the 5-pin M12 connector provides a robust, weather-resistant, and polarity-protected connection. The IP67 protection rating makes the sensor dust- and waterproof, suitable for outdoor use. Designed as a reflective photoelectric sensor, it detects any print marks in demanding industrial environments.