Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are known for having very low coefficients of thermal expansion, making them resistant to thermal shock, more so than any other common glass. Such glass is less subject to thermal stress and can withstand the temperature fluctuations of the heated bed. Borosilicate glass is sold under such trade names as Kimax, Pyrex, Endural, Schott, or Refmex. Dimensions: 12″ x 8″ x 4″
