Cylinders, used in the lab to measure the volume of a liquid, are manufactured from glass or plastic and may feature graduations to aid in determining volume. Cylinders may come with a hexagonal base or fused round base for stability and to prevent spilling. Cylinders are generally considered more accurate than beakers and flasks for measurement purposes but are not recommended for volumetric analysis. Borosilicate glass cylinders provide ideal durability and corrosion resistance, while plastic cylinders are noted for their impact and chemical resistance and can be autoclaved. Plastic cylinders also do not form a meniscus, allowing liquids to remain level for measuring purposes.