Bell jars are used in conjunction with a vacuum fitted base to form and maintain a low-pressure environment. Ground flat rims provide the tightest seal for minimum leakage. Round bottom styles with the molded solid knob handles are easy to remove to access items. The glassware is optically clear for best experimenting visibility. It is using when requiring a low-quality vacuum atmosphere or simply protecting delicate materials from harmful surroundings. This high-quality bell jar is made of clear glasses and has a dimension of 150×250 mm.