The interoperation between UMTS and GSM in the handover context includes the following method steps. The reflection structure and the light source modules are disposed at a periphery of the touch surface. A source in a first liquid transfer can act as a destination in a subsequent liquid transfer, and vice versa. The reference swap may be a credit default index swap. The target is attached to a bolt that can be threaded through the tank insulation until the end of the bolt makes snug contact with the tank shell.