The Nutriculture Universal Elbow (13mm) is a premium IWS spare part. It's suitable for use with DWC, Flood and Drain, and Dripper systems. The Universal Elbow fits into the sealing gland of the IWS hydroponic grow systems. The unit fits onto the end of a pipe. It provides an efficient way to turn the corner into the Outer Pot. The barbs of the product hold it securely in place. The smooth end fits into an Outer Pot's or Brain Pot's IWS sealing gland.