Set of four 250 mL Erlenmeyer flasks made from borosilicate 3.3 glass, each with a screw cap for secure closure. This combination of glass quality and cap design protects contents, reduces evaporation, and supports reuse in everyday lab work. Key benefits Secure screw cap minimizes evaporation and contamination during storage and heating. Borosilicate 3.3 glass provides chemical durability and good temperature resistance for routine lab use. Erlenmeyer shape enables easy swirling, mixing, and observation of contents without splashing. Clear glass allows straightforward visual monitoring of reactions and contents. Durable and reusable, suitable for repeated laboratory applications. Key attributes Functionality: Erlenmeyer flask designed for mixing, heating, and storing liquids with a secure cap. Compatibility: Broad chemical durability with common laboratory solvents and reagents. Size and capacity: 250 mL capacity per flask. Material: Borosilicate 3.3 glass for improved thermal and chemical performance. Closure: Screw cap provides a tight seal to reduce evaporation and contamination. Package quantity: 4 pieces included in the set. Use cases and applications Mixing and heating small reaction volumes in educational, research, or clinical settings. Temporary storage of prepared samples or reagents with reduced evaporation and exposure. Classroom demonstrations or introductory experiments where secure containment and easy observation are beneficial. Care and handling Hand wash or gentle dishwasher possible if approved for the cap design; avoid harsh abrasives to preserve the cap seal. Avoid sudden or extreme temperature changes beyond the glass's rated tolerance to minimize thermal shock. Inspect caps and threads regularly to maintain a reliable seal. This 4piece 250 mL borosilicate Erlenmeyer flask set with screw caps provides reliable performance for routine laboratory tasks, combining practical storage capability with the convenience of secure closures and reusable glassware.