This is TN LAB's Erlenmeyer graduated conical 250ml 1L glass flask with matching 24/25 tapered glass stopper. The flask has a tapered neck, printed graduations, with a marking area. With a Borosilicate 24/25 jointed glass stopper, matched to this exact jointed flask insures a tight seal. Borsilicate glass is highly leach resistant to most chemicals and has broad temperature limits -180 to 500 C. All TN LAB labware is manufactured to ISO: 9001 standards. There are many applications for Erlenmeyer flasks: the heating of solid and liquid chemicals, evaporation of water or solvents, mixing and dissolution of chemicals into liquids, chemical reactions of organics and/or inorganics, and collection of samples for analysis or treatment, to name a few.