Cylinders are calibrated to contain at 20º C and are provided with SAFE-GUARD bumpers (25mL and larger) and hexagonal bases that are flat ground for added stability. Designed from ASTM E1272 Style 1 Class A requirements. The primary function of a "to contain" cylinder is to receive liquids where volumetric calculations are based solely on the volume contained within the cylinder. "To contain" cylinders are frequently used as receivers for distillation procedures.