Abstract: A nozzle has a body provided with multiple laminar flow passages to generate multiple laminar flows when air is exhausted from the nozzle into a barrel of a random selection machine. When air is blown into a barrel through the nozzle, the airflow exhausting out from the blower will be compressed by the laminar flow passages in the nozzle. The airflow will be divided into multiple jetting laminar flows due to the passages even when turbulent flow has generated. Accordingly, the speed of the air entering into the barrel of the selection machine through the nozzle is high such that numbered balls can be gathered evenly.