Southern Labware offers a full range of neoprene and cork stoppers. Cork stoppers are chemically inert, moisture resisant and effective for both liquid and solid mediums. Neoprene stoppers can be used in areas where rubber would be attacked by reagents or solvents. Synthetic neoprene stoppers have good resiliency and shelf-life. They withstand petroleum products and oils as well as most inorganic acids and bases.