Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE. The order form located on the outside of the tube covers provides a secure seal. The polypropylene material is also heat resistant and chemically inert. The manual override provides a positive seal. The hinged closure provides extra security during centrifugation. Ordering Information: Tubes come complete with either a Snap-Lock DS Closure or an Auto-Close Cap. Choose the size that corresponds to the diameter of the tube you are closing. If the cap is not the same size order one size larger. Specifications for Nalge Nunc Centrifuge Tube Closures Polypropylene NALGENE DS3111-0032 : ClosureNo.: 32 Fits TubeDia. mm: 31.5 Fits TubeVol. mL: 100 NNI No.: DS3111-0032 (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 DS3111-0032/ 21010-976 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 DS3111-0032