Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE. Closures are in the form of a polypropylene plug that is inserted in the center of the tube. They are easily removed with a flattened nose (screwdriver or other) and function as a plug to keep the tube closed and to absorb spin cycle energy. The plug itself can also be removed by heating to shatter it. Manufactured without a handle. Manufactured with a Polybrominated copolymer. To open insert the labeled end into the slot then place the disc inside the center groove then place the disc down into the groove and firmly swab closed. There is an anti-seize on the inside of the lid and a venting hole at the top. The neck of the tube does not meet the closure requirement. Specifications for Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE DS3111-0018 : ClosureNo.: 18 Fits TubeDia. mm: 18 Fits TubeVol. mL: 16 NNI No.: DS3111-0018 (Please note that the description and stock photo may not correspond to the specific model listed above) We offer only genuine Nalge Nunc products authorized for sale in the U.S. and other markets so you can be sure that you are buying authentic Centrifuges with a full manufacturer's warranty in addition to our own 100percent Satisfaction Guarantee. We are your premier online distributor for Nalge Nunc Centrifuges. 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 Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE DS3111-0018/ 21010-911 we carry a full complement of Centrifuges as well as other product offerings from Nalge Nunc. We also carry a full line of Nalge Nunc accessories to help meet your laboratory and scientific needs. For a complete selection of Nalge Nunc Centrifuges please visit our Nalge Nunc page. For more brand name Centrifuges please visit our Centrifuges store section. To see our complete line of lab medical industrial and scientific products please see our science and lab equipment online catalog. Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE DS3111-0018