The Tx Unit 3 allows coaches to start multiple Fx Chips at the same time. The Tx Unit 3 is activated by the a loud sharp noise such as a gun or a clap. 
 
Ideal for racing multile athletes at training or at an athletics event. 
 
The Tx PowerUnit 3 can start up to four track lanes when placed at the center of the four lanes
 
To gather the time at the end of the race simply place the required number of tx Junior Transmitters at the required distance.