Hello Elmar Moes,
Sorry that we don't have the plan to make the water block for Radeon RX 6800XT/6900XT MERC 319 now. It is not the reference card.
We only have the water block for 6800XT/6900XT reference card now.
https://shop.bitspower.com/index.php?route=product/product&product_id=7945&search=6900
