The ACO(model: sprit or D-sprit)archery timing device is combined with the electronic time down-counting equipment and signal lamps, and it is the developed according to the rules of international archery Federation (FTTA).Its function is especially fit for the archers’ training and small competitions. It is consists of a LED display box (including a battery and a charger) and a remote-control unit. The LED display box is made of microprocessor technology and quartz technology. which can ensure the product be accuracy and reliable.