Made of high borosilicate glass, heat for long-term laboratory experiment use. Cylindrical flat bottom design places steadily on heating mantle and inlaboratory bench without tipping over. Practical three-neck reserved ports for flexible installation of various inlaboratory accessories for multi-step experimental operations. Precision ground mouth interface for tight connection with distillation and other inlaboratory glassware parts. Perfect for distillation, synthesis, reflux reaction and various laboratory heating experiments.