IDEC HS7A-DMC Non-contact magnetic safety interlock switches perform the same functions as standard mechanical safety interlock switches, but are designed to be used in applications where non contact is desired between the switch and its actuating key. It's also being used where space is at a premium. It's also very light weight - only 3.6 oz. Food & beverage and pharmaceutical applications require that no contaminants be trapped in or around devices. A precise door guide is not possible. Applications demanding zero operating force, such as lightweight or plexiglass doors, where cracking or breakage is possible with standard mechanical safety interlocks. IZUMI Non-contact devices have no inherent operating force. When there are alignment issues with the switch and actuating keys of mechanical safety interlock switches. Machine doors are subjected to heavy vibration. Wash down applications where a standard mechanical safety interlock switch would be more difficult to clean, especially in the actuating key receptacle.