These are 2 subsets (300^3 cells each) derived from larger 1024^3 cosmological MHD simulations produced using ENZO on Piz-Daint (CSCS) by F.Vazza& collaborators. In these "primordial" models we impose an initial seed field of ~1nG (comoving) at the begin of the simulation (z=38). In the "P" run we initialised a uniform field aligned along the X,Y,Z direction, while the "Pz2" run is for a field aligned with the Z-direction only. These dataset are extracted around a massive cluster at z=0, and give gas density, Dark Matter density, temperature and magnetic field components in cgs units [g/cm^3, K and Gauss]. Each cell has a comoving size of 83.3 kpc. The data are written in HDF5 format (https://support.hdfgroup.org/HDF5/). We additionally provide also .fits maps of the X and Z projection across the box, showing the volume weighted mean density, DM density, temperature, |B| and Bz. For more details on the simulations please refer to http://cosmosimfrazza.myfreesites.net/magnetic-models Vazza et al. 2017 CQG (http://iopscience.iop.org/article/10.1088/1361-6382/aa8e60)