Control flow as you transfer liquid into a new container. Also known as separatory funnels, these funnels were originally used in labs to let liquid mixtures separate, like oil and water, to dispense them by density. But they have broader utility too—the stopcock lets you adjust the flow of any liquid from a trickle to a stream. Unlike most funnels, they’re enclosed at the top. Cap them to prevent spills as you move them around your station. Made entirely of borosilicate glass, they withstand high temperatures and harsh chemicals. The glass doesn’t leach, so it won’t affect the contents. All meet strict ASTM standards for laboratory glassware material and dimensions.