20 mm stainless expansion union with brass nuts and silicon seals. Connect to any 20 mm bsp fitting with a flat shoulder for the seal to seat on. (Photo shows 20 mm flexible hose nipple, not included in the auction). These are for joining solar water heating panels so can handle high temperature. We have excess of these from single panel installations. Auction is for 1 union with 2 silicon seals. This item is "in Trade" so a GST invoice will be issued to the winner.