Most industrial applications use Contrinex safety light curtains with hand resolution (30 mm). These devices provide cost-effective protection and an appropriate safety distance from the hazard in the machine. Contrinex types are particularly strong and well sealed in housings with an enclosure rating of IP65 and IP67. Slim (26 mm x 26 mm) or standard (42 mm x 48 mm) light curtains are available as Type 2 or Type 4 devices according to IEC 61496-1 and -2 and ISO 13849-1. The protective length extends up to 1.9 meters and short response times allow the user to reduce the safety distance from a hazardous application. Two communication channels can be selected to avoid cross-talk between two pairs of light curtains that may be installed next to each other. If the hazard in the application is limited and the risk assessment confirms that no severe injury can be caused, Type 2 light curtains are preferred. If the hazard is serious, Type 4 devices are required. Most applications use Type 4 to ensure the highest safety level. However, for some applications Type 2 is more than adequate. Type 2 devices are also suitable when the machine needs to be protected from the user, rather than the contrary. For example: a small, high-precision, pick-and-place robot is unlikely to injure the user during operation, but the user could damage or disrupt the robot. With protection up to 12 meters (standard housing) or 8 meters (slim housing), these products can be used in a wide range of applications, including large assembly lines for which a long distance is specified. Typical applications are press machines, metal forming machines and automotive assembly lines.