Single-beam photoelectric safety switches comprise either self-testing senders and receivers or testable senders and receivers combined with an evaluation unit. They have long sensing ranges and come in a variety of types and sizes. They comply with Type 2 or Type 4 to EN 61496, and PL c or PL e to EN ISO 13849. Fields of application include robots, processing machinery, machining centers, palletizer systems, high-bay warehouses, and transfer lines.