Round bottom, heavy wall, pressure rated flask. All flasks come complete with a solid PTFE plug seal with front seal FETFE o-ring for better containment of product. Vessels are tested at 1.5x for a working pressure rating at 60PSI at 120°C. Flask has a top joint with #15 Ace-Thred. Note pressure ratings are at 120°C for this product. Always use shields and eyewear when using pressure vessels.