The Safety Emergency Unit SEU-4 can be easily integrated into an existing electronic SRF safety chain thanks to its M12 connection. This meets the requirements of the Machinery Directive, which states that every system must be equipped with an emergency stop. Additionally, the issue of error masking is eliminated due to the electronic approach. The clearly visible LED status indicator allows the condition of the emergency stop switch to be seen from a great distance. By default, the emergency stop switch achieves protection class IP65. When combined with the silicone protective cover SEU-WDC, it reaches protection class IP69. The protection class at the connector is IP67 and can be further increased through concealed installation.