Iron base, XRF set of 12 discs (7 mm), see BS-191-7MM, BS-182-7MM, BS-193-7MM, BS-188A-7MM, BS-189A-7MM, BS-187A-7MM, BS-179A-7MM, BS-183-7MM, BS-186A-7MM, BS-190-7MM, BS-180A-7MM, BS-181A-7MM