" These Labflow, USA Lab Glass Stopcock valve is used to regulate the flow of gases or liquids into reaction systems and is made of 3.3 borosillicate glass. They fit in the top of the Reactor's Receiving Flask and Material Flask. \n<p style=\"text-align
" These Labflow, USA Lab Glass Stopcock valve is used to regulate the flow of gases or liquids into reaction systems and is made of 3.3 borosillicate glass. They fit in the top of the Reactor's Receiving Flask and Material Flask. \n<p style=\"text-align