[en] A modularized NaI detector with close to 4π geometry can provide unique information on the decay γ-radiation from highly excited nuclei. GSI Darmstadt, the Max-Planck-Institute (MPI) for Nuclear Physics and the University of Heidelberg have joined in a collaboration to realize such a detector. The detector has the shape of a spherical shell with a free inner radius of 25 cm and a thickness of 20 cm and comprises 162 individual modules of equal solid angle. This contribution explains our special choice of configuration and gives an outline of the present status of the mechanical and electronic assembly