The bypass hose from the thermostat housing to the top of the water pump? It's a Gates hose, part #18925. Bar code # 0 72053 32095 4.
You'll also need 2, 12-27mm hose clamps. When you buy the new one, order a spare for the shelf. Waiting for hoses to come in while your stranded sucks. I get mine at O' Reilly's Auto parts.