These heavy duty 3.3 borosilicate glass round bottles can be used for storage as well as mixing and sampling. They include a linerless, one-piece autoclavable blue polypropylene plug seal GL45 threaded cap with a drip-free pouring ring. Max temperature of 140 degrees Celsius (284 degrees Fahrenheit). NON-ALKALINE-EARTH BOROSILICATE GLASS (BOROSILICATE GLASS 3.3): The B2O3 content for borosilicate glass is typically 12-13% and the SiO2 content over 80%. High chemical durability and low thermal expansion (3.3 × 10−6 K−1) - the lowest of all commercial glasses for large-scale technical applications - make this a multitalented glass material. High-grade borosilicate flat glasses are used in a wide variety of industries, mainly for technical applications that require either good thermal resistance, excellent chemical durability, or high light transmission in combination with a pristine surface quality. Other typical applications for different forms of borosilicate glass include glass tubing, glass piping, glass containers, etc. especially for the chemical industry. ALKALINE-EARTH-CONTAINING BOROSILICATE GLASSES (BOROSILICATE GLASS):In addition to about 75% SiO2 and 8-12% B2O3, these glasses contain up to 5% alkaline earths and alumina (Al2O3). This is a subtype of slightly softer glasses, which have thermal expansions in the range (4.0-5.0) × 10−6 K−1.