The O-21 miniature series with IO-Link is available in four different versions. The OH21 photoelectric proximity switch with background suppression detects even the smallest differences in height. The OR21 retro-reflective sensor is suitable for use in extremely cramped installation situations (e.g. in a label dispenser).

The OT21 photoelectric proximity switch uses a large light spot to reliably hide gaps and holes during object detection. According to the manufacturer, the one-way photoelectric switch pair OS21 / OE21 is space-saving and can be integrated into a guide rail, for example.