Flask with oblique neck and side socket. Made of high quality, heavy duty Borosilicate glass. 250ml capacity. Size 24/29 center socket, size 14/23 side sockets. Flask measures 5" tall, 3" width at the widest point. Perfect for any home, school, or professional science laboratory. Flask with oblique neck and side socket. Made of high quality, heavy duty Borosilicate glass. Size 24/29 center socket, size 14/23 side sockets. Flask measures 5" tall, 3" width at the widest point. Perfect for any home, school, or professional science laboratory. Eisco Labs Borosilicate glass has the following heat tolerances: Strain Point -515°C | Annealing Point 565°C | Softening Point 820°C