These heavy duty PYREXPLUS® round bottles have a protective PVC coating to help prevent glass from shattering and reduces spills. Bottles are autoclavable at 121°C and resistant to thermal shock. Bottles have GL45 threaded necks and come with autoclavable, one-piece, teal colored polypropylene plug seal caps with drip-free pouring rings. Glass bead indicates full capacity line. Teal enameled graduations and marking spot. Covered by U.S. Patent 4,940,613. Caution: Do not place these bottles over direct heat or flame or heat above 121°C moist heat or 110°C dry heat.