This device is a relay box that switches a potential-free contact with the transmitter from the Mistral series. The power supply is provided by a 3V lithium battery or optionally by a power supply of 8 to 12V. After activating the associated transmitter, the relay in the box switches on for the set duration. Multiple transmitters and receivers can be combined. Up to 16 transmitters can be learned by the receiver. Timer function ranges from 1 to 1000 seconds. External power supply is possible.