Bel-Art Ring Vinyl Coated Lead Open 2. For those who are not familiar constant temperature equipment is a general-purpose heat-expanding oven that provides a uniform heat over a wide range of temperature ranges. The only variable is the temperature. During heating the heat expands via a process called superheating. The heat expands the bubbles in the liquid resulting in the creation of a larger surface area of the bubbles and an associated loss of heat. Superheaters use this constant temperature equipment to heat-expand the sample vessels to the desired temperature. Once the temperature has been established the rings function as a heat-expanding oven with a small raised base. Once the heat source is applied the rings solidify to form a hermetic seal around the neck of the vessel. Once the heat source is applied the open ring expands to fill the space between the two sealing rings thus preventing any liquids from dripping onto the stand or ring. The flat ring which is beaded is twisted on and tapered at one end to conform to the flare of the vessel neck. The flat ring prevents flares and inclusions such as dried blood and scalding and loss of heat from boiling or distilling vessels. Made of lead and coated with green Vikem vinyl. Pull the ring apart to accommodate a wider vessel. As a general rule separation distances for similar items of the same size are not to exceed 5 mm. Specifications for Bel-Art Ring Vinyl Coated Lead Open 2 183084000 : Description: RING VINYL COATED LEAD OPEN 2 (Please note that the description and stock photo may not correspond to the specific model listed above) We offer only genuine Bel-Art products authorized for sale in the U.S. and other markets so you can be sure that you are buying authentic Baths Ovens Incubators and Cryogenics Storage with a full manufacturer's warranty in addition to our own 100percent Satisfaction Guarantee. We are your premier online distributor for Bel-Art Baths Ovens Incubators and Cryogenics Storage. 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 Bel-Art Ring Vinyl Coated Lead Open 2 183084000/ 74950-104 we carry a full complement of Baths Ovens Incubators and Cryogenics Storage as well as other product offerings from Bel-Art. We also carry a full line of Bel-Art accessories to help meet your laboratory and scientific needs. For a complete selection of Bel-Art Baths Ovens Incubators and Cryogenics Storage please visit our Bel-Art page. For more brand name Baths Ovens Incubators and Cryogenics Storage please visit our Baths Ovens Incubators and Cryogenics Storage store section. To see our complete line of lab medical industrial and scientific products please see our science and lab equipment online catalog. Bel-Art Ring Vinyl Coated Lead Open 2 183084000