You cannot connect mains water directly to your caravan as the internal piping is unsuitable. You will need a pressure reducer giving a maximum output of 30 psi (2 bar).
Truma supply the Waterlines - part 129440 for the Ultraflow inlet and 130483 for the Crystal Mk 2 inlet. Whale also do the Aquasource for the Whale Watermaster inlet and this is our ref. 127867. We also supply the reducing valve as a separate part, our ref. 137879.