Shelly is not a name that every smart home enthusiast is familiar with in the U.S., but it is a well-established brand in Europe and other parts of the world. Doug Roberson, chief technology officer of Allterco Robotics U.S. provided me with a few Shelly products to test.

Shelly smart home products are manufactured by Allterco Robotics, one of seven companies that make up the holding company Allterco whose headquarters is in Sofia, Bulgaria. Allterco has 20 years of experience in mobile, value-added products and services. The company is expanding beyond the telecommunications industry and is now focusing on the development and distribution of IoT products and solutions.
Allterco Robotics introduced its Shelly line of smart home IoT products in 2018. These products are sold in 120 countries around the world, and the company opened an office in the U.S in 2020.

These include:
Shelly 1: Provides control of a single circuit through its internal relay
Shelly 1PM: Provides control of a single circuit through its internal relay and can measure the power used by lights / appliances connected to the controlled circuit
Shelly 2.5: Provides control of two circuits through its internal relays and can measure the power used by lights / appliances connected to the controlled circuits
Shelly EM: Provides power measurements of up to two circuits by using clamp on current transformers and can control a relay connected to its contactor control terminal. The relay can then control a circuit with any number of lights/appliances connected to it.

All of these are very small, compact IoT devices. In fact, they are each only about the size of two Oreo cookies stacked on top of each other!
The Shelly 1, Shelly 1PM, Shelly 2.5, and Shelly EM all connect through Wi-Fi to an 802.11 b/g/n network and have internal web servers that are used to configure and operate the device using a browser. Each device can also be operated and configured using the following:

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