The Freelap Tx Touch Pro transmitter can be used for block starts and three-point stance such as the 40-yard dash. The transmitter is compatible with both the Freelap Sprint Coach and Pro Coach BLE. The transmitter is placed on the start line. The athlete presses the button with their thumb. As the athlete begins to sprint, their thumb releases the button, and the transmitter emits a magnetic pulse that starts the Freelap watch or FxChip.