VWR Magnetic Rare Earth Stir Bars. It is for this precise reason that magnetic stirring bars were invented. These elliptical shaped magnets are built to hold up to tremendous forces and vibrations allowing powerful magnetic stirring for long periods of time. The discovery of the magnetization of a material increases its attraction to that substance. Thus if a strong magnet is applied to a material it will attract other magnets of the same type and strength. Over time all magnets will slowly weaken and eventually lose their strength. However rare earth magnets will retain their special attraction. Specifications for VWR Magnetic Rare Earth Stir Bars 001.2615.RE : DimensionsDia. x L mm (in.): 10 x 15 (3/8 x 19/32) (Please note that the description and stock photo may not correspond to the specific model listed above) We offer only genuine Cowie products authorized for sale in the U.S. and other markets so you can be sure that you are buying authentic Laboratory Apparatus with a full manufacturer's warranty in addition to our own 100percent Satisfaction Guarantee. We are your premier online distributor for VWR Laboratory Apparatus. 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 Magnetic Rare Earth Stir Bars 001.2615.RE/ 89030-552 we carry a full complement of Laboratory Apparatus as well as other product offerings from Cowie. We also carry a full line of VWR accessories to help meet your laboratory and scientific needs. For a complete selection of VWR Laboratory Apparatus please visit our Cowie page. For more brand name Laboratory Apparatus please visit our Laboratory Apparatus store section. To see our complete line of lab medical industrial and scientific products please see our science and lab equipment online catalog. VWR Magnetic Rare Earth Stir Bars 001.2615.RE