Reagent flasks (or bottles) are essential laboratory glassware designed for storing, mixing, or heating chemical reagents, typically made from high-quality 3.3 borosilicate glass for superior chemical and thermal resistance. Key specifications include GL 45 screw caps or ground glass stoppers, capacities ranging from 25 mL to 10,000 mL, and options for clear or amber (UV-protective) glass, often conforming to ISO 4796-1 standards