Labvida Glass Boiling Flasks are made of 3.3 Borosilicate glass material which has excellent chemical durability for contamination-free results, heavy duty and reusable, designed for great shock resistance, uniform wall thickness and geometry permits very uniform heating. <br><br> Contains 2pcs of Vol. 250ml Glass Boiling Flasks of Flat Bottom. <br><br> Provide uniform heating of liquids for quality testing, sampling, and research in chemistry, education, research, and life science applications. <br> Also could be used as wine decanter, vase, painting and etc.<br><br> After-Sales Service:<br> Labvida always persists in “Quality First, Customer First”.<br> We are 100% dedicated to your complete satisfaction. Any questions or suggestions on our products or service, please do feel free to let us know. Appreciate your support and patience.