This 250ml Florence boiling flask is crafted from high-quality, heavy-duty borosilicate glass, featuring a wide neck, flat bottom, and beaded rim. It stands 5.25" tall with a 3.25" bottom diameter and a 3" neck length. Ideal for both science and home laboratories, it has excellent heat tolerances: strain point -515°C, annealing point 565°C, and softening point 820°C.