... diagnostic function.Aesthetic and endurable battery handle is equipped also.WG-I,II,IIB,Diopter compensation: ±1,±2,±3,± ... 30WG-III,Diopter compensation: ±1,±2,±3,±4,±6,±8,±10,±15,±20,±25,+40WG-IIIE,Diopter compensation: ±1 ... ,±2,±3,±4,±5,±6,±8,±10,±12,±16,±20,-25WG-XP,XPB,XPC,Diopter ... compensation: ±1,±2,±3,±4,±5,±6,±8,±10,±15,±20,±25,+40Although ear specula's diameter ...