1,Flat bottom ground flask(chemistry flask) 2,High temperature resistance and corrosion resistance 3excellent optical property ... glass , heavy wall.3:Size: capacity(ML):5,, 10,, 25,, 50,,1 00,,150, ,250,, 500,, 1000,, 2000,, 3000,, 5000,, 10000,, 20000 ... research, teaching, medicine, and petroleum chemical industries. glass flat bottom flask(chemistry flask)