THE UNIVERSAL TRANSMITTER WITH 433MHZ, TX4UNIF The TX4UNIF universal transmitter has a white LED indicator and operates on the 433MHz frequency. As a universal transmitter, it can be used for the entire Evolution series and older drives (with 433MHz up to 1997). The transmitter has a design based on a modern and attractive vehicle key. The big buttons of the universal transmitter also increase ease of use and make it possible to control up to four doors.