The Mn12 complex, [Mn12O12(CH3COO)16(H2O4][unreadable]2CH3COOH[unreadable]4H2O behaves as a single-molecule magnet which exhibits a macroscopic quantum tunneling of magnetic moment. Here we apply 95 GHz EPR at cryogenic temperatures to confirm an unusual S=10 spin state and to determine zero-field-splitting parameters for single crystals of Mn12 acetate.