This item is a professional flask. Heavy-duty glass uniform wall thickness distribution, durable and practical. Solid base design, for more stable placement, reducing measurement error. The clear scale can help you measure more accurately. Widely used in schools, factories, scientific laboratories and other fields. Features -Color: As Shown -Material: High Borosilicate Glass -Size 50ml: 8.70X5.10X1.90cm/3.42X2.00X0.74in -Size 100ml: 10.30X6.50X1.90cm/4.55X2.55X0.74in -Size 150ml: 12.10X7.10X1.90cm/4.76X2.79X0.74in -Size 250ml: 15.20X8.60X2.40cm/5.98X3.38X0.94in -The borosilicate glass Erlenmeyer flask has High chemical durability and low thermal expansion. -Clear scale: Erlenmeyer flasks have clear and accurate scales for you to measure liquid efficiently. -Made of solid thick glass and have a good feeling. Reusable and solid quality, not easily broken. -Erlenmeyer flasks are for yeast culturing, mixing solutions, or running sample trials for beer or wine preparations. -Suitable for beginners or professional use, also the students, convenient classroom borosilicate glass Erlenmeyer flasks. Package list: 4 x Conical Flasks