Plasticoid Black Rubber Stoppers Solid 135M290 Each. Combining top-notch and uncompromising quality with an affordable price the Plasticoid Black Rubber Stoppers Solid 135M290/ 59580-502 can fulfill your laboratory needs while still offering a great value for the money. Product Category Description: Black rubber laboratory stoppers are made of natural rubber and are solid round or oval with rounded sides. Large flat bottoms help to center the stoppers in the necks of test tubes and cylinders. Round bottoms show that the stoppers have a slightly increased thickness and are ideally suited for applications with increased fluid throughput as is the case with many technical laboratories. The larger size has a slightly increased surface area and is the best suited for medium viscous fluids. The stoppers express heat in the form of a coke flame rather than coke crystals so that contamination to a greater degree is minimized. Specifications for Plasticoid Black Rubber Stoppers Solid 135M290 : Size: 131/2 Dia. of Top mm: 75 Dia. of Bottom mm: 62 Length mm: 35 No./lb. (Approx.): - Unit: Each (Please note that the description and stock photo may not correspond to the specific model listed above) We offer only genuine Plasticoid 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 Plasticoid 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 Plasticoid Black Rubber Stoppers Solid 135M290/ 59580-502 we carry a full complement of Laboratory Consumables as well as other product offerings from Plasticoid. We also carry a full line of Plasticoid accessories to help meet your laboratory and scientific needs. For a complete selection of Plasticoid Laboratory Consumables please visit our Plasticoid 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. Plasticoid Black Rubber Stoppers Solid 135M290 Each