This coolant hose runs from the passenger cylinder head to the coolant distribution tower.
#14 on attached schematic
Note: This specific hose is typically found on 88-91 Vanagons. Earlier 2.1 WBX models had a slightly different hose, 251121130A, which can be found here.
Suitable for 1988-91 Vanagon
Volkswagen Part Number 251121130B
Alternate Part Number JP-1124-0