Omron separates their limit switches into three different categories, general purpose limit switches, typically found in processes or part of the industrial process that need maximum robustness and reliability. Next are safety switches are just like general purpose switches, except when they fail/wear out, they fail with their electrical circuits in the open condition, required for safety rated applications. And lastly basic limit switches, which are smaller versions of the general-purpose switches with a smaller range of motion. These are generally used for less demanding motion applications.