VWR Chlorobutyl Serum and Lyophilization Stoppers West Pharmaceutical Services Serum Stoppers. Combining top-notch and uncompromising quality with an affordable price the VWR Chlorobutyl Serum and Lyophilization Stoppers West Pharmaceutical Services Serum Stoppers 19700035/ 80079-874 can fulfill your laboratory needs while still offering a great value for the money. Product Category Description: Stoppers are molded from elastomeric formula 4432/50 Gray. This formula has extremely low levels of organic and metallic extractables and does not contain plasticizers 2-Mercaptobenzothiazole nitrosamine precursors or natural rubber latex. Enhanced stoppers are treated with FluoroTec fluorocarbon film for an excellent barrier against organic and inorganic extractables to minimize interaction between the stored product and the closure. The low surface energy of fluorocarbon film also reduces protein adsorption and provides lubricity without the need for silicone oil. The film is applied to the top and bottom surfaces of the stopper. The film on the top helps prevent stoppers from sticking to lyophilization chamber shelves. In addition to the flurocarbon film on the top and bottom of the stopper enhanced lyophilization stoppers are coated with a cross-linkable polydimethylsiloxane on the underside of the flange. This coating helps to reduce friction as stoppers pass through filling lines and helps reduce the level of subvisible particulate matter. Enhanced stoppers are also ready for sterilization without further preparation. They are packaged in double sterilizable bags designed for direct entry into sterilization units. Each shipment also includes a certificate of analysis. All stoppers are manufactured in cGMP facilities and tested for quality. Stoppers meet USP Ph. Eur. and JP requirements. Specifications for VWR Chlorobutyl Serum and Lyophilization Stoppers West Pharmaceutical Services 19700035 Serum Stoppers : Type: Enhanced Size mm: 13 West No.: 19700035 (Please note that the description and stock photo may not correspond to the specific model listed above) We offer only genuine VWR products authorized for sale in the U.S. and other markets so you can be sure that you are buying authentic Laboratory Consumables with a full manufacturer's warranty in addition to our own 100percent Satisfaction Guarantee. We are your premier online distributor for VWR Laboratory Consumables. We are an authorized supplier to all federal and state government agencies as well as to research and educational institutions and can facilitate volume orders on many types of laboratory equipment lab consumables and other products to help fulfill your specific needs. We offer Free Shipping and FREE USPS shipping to APO and FPO addresses on all orders in our store over 49. Please refer to our APO/FPO Shipping and Export Restrictions for more information on export to APO/FPO addresses. In addition to the VWR Chlorobutyl Serum and Lyophilization Stoppers West Pharmaceutical Services Serum Stoppers 19700035/ 80079-874 we carry a full complement of Laboratory Consumables as well as other product offerings from VWR. We also carry a full line of VWR accessories to help meet your laboratory and scientific needs. For a complete selection of VWR Laboratory Consumables please visit our VWR page. For more brand name Laboratory Consumables please visit our Laboratory Consumables store section. To see our complete line of lab medical industrial and scientific products please see our science and lab equipment online catalog. VWR Chlorobutyl Serum and Lyophilization Stoppers West Pharmaceutical Services 19700035 Serum Stoppers