Based on this product's specifications, here are some alternatives and similar models
Photoelectric Fork Sensor Panasonic PM-U25-C3 U-type fork, 5–24 V DC, light/dark switching
Summary description:
Panasonic PM-U25-C3 is a U-type photoelectric fork sensor (gabel-lichtschranke) operating at 5–24 V DC with selectable light-on (hellschaltend) and dark-on (dunkelschaltend) switching modes. Designed for object detection, edge sensing and presence monitoring in automation, packaging and assembly lines where a compact fork-style sensor provides reliable non-contact detection.