A hollow extension tube or extension assembly aids in increasing the quantity of any inhaled or aerosolized substance delivered to a patient's lungs from an inhaler or source. The length of the extension tube reduces the velocity and increases the temperature of the aerosolized substance, easing inhalation. The interior surface of the hollow extension tube has anti-static properties which reduces the amount of aerosolized substance trapped by the interior surface of the hollow extension tube. The interior surface of the extension tube may be formed of cardboard.