A study of the EPR spectra of aspin s=1/2 four-nuclear single molecular magnet with D4h symmetry, having ferromagnetic nearest neighbor and local interactions such as the Dzyaloshinsky-Moriya (DMI), axial, and azimuthal anisotropy, was performed. The evolution of the spin tetramer EPR spectra is described as a function of the spin-spin interaction parameters. The impact of spin-mixing on the splitting of spectral lines is considered for intermultiplet and intramultiplet transitions. The study yields simple relations that connect the parameters of isotropic exchange interaction, DMI, and local anisotropy to the frequency ratios of certain spectral lines.