●【HIGH-QUALITY MATERIAL】 Select high-quality, environment-friendly and high-density synthetic cork. and the thickness is 30mm/1.18in. ●【COMPLETE SPECIFICATIONS】4 different sizes of cork flask holders, Providing excellent support to 250ml - 1000ml round bottom flasks. ●【HIGH QUALITY CORK FLASK HOLDER】Featured with acid and alkali resistance, heat resistance, heat insulation.Order with confidence and enjoy. ●【PLACE STABLY】The laboratory flask cork stand has good elasticity, strong friction coefficient, keeping round bottom boil flasks upright!Stop them from rolling around. ●【WIDE APPLICATION】Used in various laboratories, chemistry classrooms,hospital,Chemical plant,Home lab.