Across International Heavy Wall Round Bottom 2-Neck Flask, 2LAi 2L, 24 40 standard taper joint, heavy wall, round bottom 2 neck flask with one vertical 24 40 neck, and one angled 24 40 side neck. Glass material: high borosilicate glass 3. 3. Glassware does not have warranties. Glassware may have minute blemishes that will not affect the function. If you believe there are imperfections on your glassware, please contact us. We check all our inventory and make sure no defective glassware is sent to our customers.