Used for incubating diluted samples to determine biological oxygen demand.

• Made of high quality borosilicate 3.3 glass
• Shoulder radius design facilitates air inside the bottle to be forced out during filling
• Includes a tight fitting, ground glass pennyhead stopper

Interchangeable, tight-fitting ground glass pennyhead stopper with a 18/19 cone prevents air exchange. Autoclavable, with superior chemical durability. Low temperature gradient - can withstand high temperatures and thermal shocks.

Eisco borosilicate glass has the following heat tolerances:
- Strain point 515 °C
- Annealing point 565 °C
- Softening point 820 °C