Specification Brand : DONLAB BulletPoint1 : Diameter: 200mm/7.874" approx BulletPoint2 : The watch glass is made of Borosilicate 3.3 glass with a slightly concave center. BulletPoint3 : Monolithic watch glass thickness about 2mm BulletPoint4 : The watch glass not only can be used for vaporizing liquid, but also can be used as a lid for other chemical containers. BulletPoint5 : NOTE: 1. The watch glass cannot be heated directly by fire. 2. Please check the size before purchasing. Select the watch glass of the corresponding size according to the diameter of the instrument. It is recommended to choose a watch glass that is 1cm larger than the diameter of the instrument for easier use. ExternallyAssignedProductIdentifier1 : 0708257594821 ExternallyAssignedProductIdentifier2 : 708257594821 ItemName : DONLAB AFA-0200 10pcs 200mm Diameter Watch Glass Cover Lids for Beakers & Flasks Lab Watch Glasses Boxed/10 Pcs ItemPackageDimensions_Height : 1.97 inches ItemPackageDimensions_Length : 5.91 inches ItemPackageDimensions_Width : 5.91 inches ItemPackageQuantity : 1 ItemTypeKeyword : science-lab-watch-glasses Manufacturer : DONLAB Material : Borosilicate 3.3 glass NumberOfBoxes : 1 NumberOfItems : 10 PartNumber : AFA-0200 ProductDescription : This series of products include Glass Watch Glass 45mm-200mm, Quartz Watch Glass 90mm,120mm and PTFE Watch Glass 60mm. The watch glass is made of hard glass and is suitable for quantitative analysis.