The present invention relates to a new class of diazepine-derivatives as chelating agents for paramagnetic metal ions, the process for their preparation, and use of such paramagnetic complexes as contrast agents, particularly suitable for Magnetic Resonance Imaging analysis. The probes have a constant thickness and a chisel-shaped tip portion. The device accesses, in response to receiving the request, a memory to determine a second address that is associated in the memory with the first address. The liquid collection arrangement is positioned within the housing construction and is oriented for receiving liquid collected from the coalescer filter and drained therefrom. The receiver has an automatic control mechanism for determining a delay time optimal to a system from the difference between a rising time of each of pulses different in pulse width and its falling time. A seal is positioned between the body and the housing.