Made of high borosilicate glass, heat for long-term inlaboratory heating and cooling cycle use. Double-layer jacketed construction allows hot and cold liquid circulation for stable constant temperature reaction. Standard single-port opening for easy connection with stirrers, thermometers and other inlaboratory accessories. Transparent glass body for clear real-time observation of internal reaction changes and liquid status. Widely applied in reaction, material synthesis and general laboratory daily experiment work.