One More Replacement Bulb & Complimentary Filter Medias: There are 2 bulbs come with this filter, which can effectively turn green water tank into crystal clear, improving the water quality. One more bulb is equipped with this filter that longer service life is ensured and the bulb can be timely replaced once the assembled one broken. Complimentary filter sponges and bio balls also speed up purifying the water. One Step To Make The Filter Running: Updated Design - Siphon Water Filling Nozzle, only one step that filling the water inlet system with water by adding water from the the water filling nozzle, water will automatically run into the filter after plugging the filter in and opening the water flow valve without any strenuous operation. Adjustable Water Flow: Adjustable water flow valve is designed to adapt to various usage scenarios. By rotating the flow regulating handle, water flow can be adjusted from maximum to minimum, even to zero.