Handheld transmitter Dickert FHS10-02 with 4 channels.
NOTE: The FHS10-02 transmitter with purple push buttons and green LED light operates at 40,685 MHz. There is also a Dickert MAHS433-04 with purple push button and yellow LED light that looks exactly like it. However, it works at 433.92MHz and is not compatible. There are also hand transmitters with a different color push buttons (red / blue) or different color LED lights, but all are NOT interchangeable.