These durable, fire-fused cells are standard rectangular spectrophotometer cuvettes with two optically-polished windows. They are made from the highest quality quartz and glass material available to ensure excellent transmission values and highly accurate results. Features of PerkinElmer Cuvettes: Material Path Length Outer Length Outer Width Capacity Size UV Quartz 50 mm 52.5 mm 12.5 mm 17.5 mL Macro