Heavy-duty, borosilicate glass, reusable bottles for general use in the storage, mixing and sampling of liquids. The threaded top provides quick and convenient access to contents and the permanent, white enamel graduations supply easy-to-read volume references. Large marking spot included. Glass bead indicates full capacity line. Each bottle includes a linerless, autoclavable, polypropylene cap and clear, drip-free pour ring attached.