Globe Glass heavy duty Erlenmeyer flasks meet ASTM E1406 specifications. Thick, heavy-duty walls improve mechanical strength and allow use in filtering applications not requiring side tubulation. Globe Glass heavy duty Erlenmeyer flasks are designed with reinforced, beaded rims for strength and resistance to chipping. • Meet ASTM E1406, Type I Specifications • Made exclusively from ASTM E438, Type I, Class A, 3.3 borosilicate glass • GlassGuard packaging system protects against transit damage • Thicker walls protect against damage • High resistance to chemicals • Uniform wall thickness • Reinforced beaded rims to resist chipping • Dual metric scale graduations • Durable white enamel printing • Large white marking area