Noritz QC-2 Quick Connect Cable for Models Nr83-Dvc， Nr981， Nrc1111，Nrc98， Ncc1991， Nc1991 to Connect 2 Units Only.<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Noritz Quick Connect Cable</li><li>Connects two identical tankless water heater models together in order to get twice the output of hot water</li><li>The product is manufactured in United States</li><li>Link two heaters together applicable models only</li><li>Easy installation</li><li>Units will automatically alternate sequencing</li><li>Allows communication between units</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41JTiW1zDOL.jpg" noproxy>