Reinforced plain rubber hose for the water pump to cylinder head bypass. Sold each.
Seven also offers this hose in an upgraded Kevlar reinforced material (AEG0484K) or in ultimate-spec blue silicone material (C-GZA2083). All of these must be installed when the head or the water pump is off of the engine.
If you need to do an emergency repair, the GZA2083 soft rubber convoluted hose kit can be installed with the head and water pump still in place, but it is still a bit of a challenging job due to difficult access.