This is a 8mm fuel primer pump bulb for marine outboard fuel system Made from superior rubber and aluminum materials, this primer bulb is built to withstand the rigors of marine environments. It's both oil-resistant and aging-resistant, ensuring long-lasting performance Designed for quick and straightforward installation, ensuring that you can get outboard engine running smoothly in no time Versatile use. Perfect for various marine outboard fuel systems Please pay attention to the direction of the arrow indicated on the bulb during installation and operation to ensure proper function and fuel flow