Pack of 10 stoppers made of solid neoprene rubber. Blue color. Each stopper measures 35mm in length, has a base diameter measuring 31mm, and a top diameter measuring 36mm. The neoprene rubber construction is suitable for use with petroleum products, minerals, oils and fats, as well as most inorganic acids and bases. Resistant to temperatures ranging from -40 to 130°C. Eisco Labs proudly manufactures its own products using state-of-the-art equipment, and following the highest standards of quality control. Each product is carefully designed by a team of laboratory professionals and experienced engineers with quality and durability in mind.