This product comes in 14mm and 19mm sizes. The downstem allows you to attach your unit easily to a water pipe and offers the adaptability you need to enhance your vaping experience. It can be used with the Solo, Solo 2, and Air 2 to improve your ride in the mist while reducing throat irritation and intensifying the tasty flavors. The Canadian-made borosilicate glass used is sturdy and durable. The Water Pipe Adapter for Arizer Air also offers a consistent flavor to bring out the unnoticeable textures. This is the ultimate accessory if you are trying to heighten the effects of your Solo or Air vape.