iButtons are electronic devices used in automation and industrial process control. They are designed to be small and tough enough to be used in harsh environments. iButtons come in a variety of forms and sizes, and include RAM, ROM and digital thermometer options. They are usually placed in a mounting bracket or a secure waterproof holder, and can be connected to a sensor, controller or distributor using a secure connection. They also come with accessories such as cables, connectors and power supplies, allowing them to be connected to devices outside of the enclosure.