... glass, With ground–in glass stopper or plastic stopper2. VOLUMETRIC FLASK grade A. amber clear neutral glass/Boro 3.3 glass ... , With ground–in glass stopper or plastic stopper3. VOLUMETRIC FLASK grade B. clear neutral glass/Boro 3.3 glass, With ... ground–in glass stopper or plastic stopper4. VOLUMETRIC FLASK grade B. amber neutral glass/Boro 3.3 glass, With ...