These black stoppers are made of solid natural rubber that stays pliable over a long period of time. Ideal for use with non-aggressive or concentrated solutions. Low sulfur content. Withstand temperatures from –25 to 70°C (–13 to 158°F). Available in solid, one-hole, and two-hole versions. Each stopper has its size marked in raised figures. All stoppers are 25mm tall. Sold as one-pound bags. Additional Info: Rubber Stoppers, 2-Hole, #5 1/2 Package Size(L x W x H): 4 X 6 X 6 (IN) Categories: Stoppers & Corks, Rubber HTS Code: 4016.93.5010 UNSPSC: 4.11225e+007 Country Of Origin: INDIA