Pack of 2 - 500ml Media Bottles with GL45 Screw Cap (Royal Blue) is a Graduated Storage bottle, made of Thick Borosilicate Glass, which is so thick that it can handle nearly any Pressure and temperature, from the most harsh chemicals to extreme heating agents. It is stable and durable, perfect for any use, plus its precise Graduation with 100ml Interval, can measure upto 500ml liquids. It is laboratory grade, but can be used for storing nearly anything.