The Sick UM30-212113 is an ultrasonic barrel-style proximity sensor in the M30 x 1.5 housing, with a detection range of 60 to 350 mm and an analogue output. It operates on a 9 to 30 V supply, making it a straightforward fit for standard 24 VDC control loops.
The 60–350 mm detection window is the usable sensing band — objects closer than 60 mm may not be reliably detected, and the maximum range of 350 mm is the far limit under ideal conditions (target size, reflectivity, temperature). For a line-down swap, verify the target distance falls within this span; the analogue output (likely 0–10 V or 4–20 mA, though the listing does not specify the exact scaling) gives a continuous distance signal rather than a simple on/off.