Oil Resistant Stoppers Neoprene Stoppers, 1 Hole, ASTM, Size #5.5, 24mm Bottom, 28mm Top, 25mm ASTM Blue Rubber Stoppers With Hole Suitable for use with petroleum products, minerals, oils, fats as well as most inorganic acids and bases. Neoprene Stoppers, Solid Blue - Size: 21mm Bottom, 24mm Top, 28mm Length - Pack of 10 · SOLID NEOPRENE STOPPERS || Pack of 10 solid neoprene rubber stoppers Blue ASTM neoprene stoppers with 1 hole , Size #5., 5: 24mm Bottom, 28mm Top, 25mm Length., Hole measures 5mm Pack of ten #5.5 stoppers made of solid, long lasting neoprene rubber. Blue color. Manufactured according to sizes recommended by ASTM standards. Each stopper measures 25mm in length, has a base diameter measuring 24mm, and a top diameter measuring 28mm Pack of ten ASTM neoprene stoppers., Blue, size #5., 5, one hole. EISCO 10Pk Neoprene Stoppers, 1 Hole - ASTM - Size Made from long lasting neoprene rubber, oil resistant, Use up to temps of 250°F / 120°C , Pack of 10