Mercury displacement contactors use liquid mercury as the contact material to make and break electric power connections in applications like transformers, capacitors, and heaters. Mercury switches provide long operational lives, fast switching, and quiet switching because they don't use mechanical armatures. Also known as mercury wetted relays, they have sealed contacts and perform effectively in dusty and oily environments. Mercury contactors must be handled and disposed of like hazardous waste. They may not be legal to use in certain states and localities. Before purchasing mercury displacement contactors, ensure you can use them in your state or locality.