General purpose limit switches are typically used in harsh or heavy industry environments where durability and reliability are most important. Omron has two general purpose limit switches, the D4A series and the WL-N series. The D4A offers a wide operating temperature range packaged in a robust metal housing with a wide array of actuator/arm options. This is useful for palletizing, injection molding, packaging equipment and lift machinery. The WL-N series is focused on environmental protection and reliability, useful for applications like machine tools, welding and automotive applications.