The Prevent Safety Detection series Safety light curtains that are electro-sensitive protective equipment (ESPE) designed for the protection of persons operating or working in the vicinity of machinery, by stopping the hazardous movement of parts as soon as one of the light beams is broken. In particular, they provide protection to help ensure the safety of personnel operating hazardous machinery but they are equally suitable for use with many other types of machines. They make it possible to help protect personnel while allowing free access to machines. The absence of mechanical protectors reduces the time required for loading, inspection or adjustment operations as well as making access easier.