ɹˈeɪsᵻz ɑːɹ tˈaɪmd ᵻlɛktɹˈɑːnɪkli jˈuːzɪŋ ɐ mᵻkˈænɪkəl lˈɛvɚ fɚðə klˈɑːk stˈɑːɹt ænd ɐn ˈɑːptɪkəl bˈiːm sˈɛnsɚ fɚðə klˈɑːk stˈɑːp.
Races are timed electronically using a mechanical lever for the clock start and an optical beam sensor for the clock stop.