DIN Rail montering holder Sonoff DRExpanded Functionality As you may know, most Sonoff products do not have the ability to be mounted on a DIN rail, which makes it difficult to place them in a distribution box. Now, with the Sonoff DR bracket, this is possible. Construction The bracket is made of fire resistant ABS V0 material. It has a blue clip that allows for easy mounting and dismounting from the DIN rail. The package includes 4 M3 screws for securing the relay to the bracket.