Smart plugs typically consist of three main components:
- Enclosure: The enclosure houses the internal components and provides protection. Common materials for enclosures include plastic, metal and ceramic.
- Plastic: Plastic enclosures are lightweight, inexpensive and insulating. However, they are not very durable and can melt in high heat.
- Metal: Metal enclosures are durable and help dissipate heat, but they need to be properly insulated. They tend to be more expensive than plastics.

- Electrical components: The main components include a microcontroller, relay, current sensor, overload protection, etc. They control the power to the plug and monitor energy usage.
- Power terminals: The power terminals, often made of brass or copper, connect the plug to the power source and the device. They must be properly insulated from the enclosure.
In summary, smart plugs contain three main parts: an enclosure to house the components, electrical components to control and monitor power, and power terminals to connect the plug. The material used for the enclosure, especially, affects the durability, safety, and cost of the smart plug. Plastic or metal enclosures are good for normal use, while ceramic enclosures provide the highest safety and durability in harsh conditions.
