Manufactured from borosilicate glass for chemical and thermal resistance. Square bottles are easier to handle, require less space on the shelf or in the autoclave and are ideal for mixing, sampling, and storage. Features include white enamel graduations, large marking spot and a glass ridge molded into the bottle to indicate full capacity. Includes linerless, one-piece, autoclavable, blue, polypropylene plug seal cap with drip-free pouring ring Do NOT have caps tightened immediately after autoclaving as the vacuum resulting from cooling can cause breakage. Not applicable for vacuum use.