Standard disposable polystyrene cuvettes with optical windows to achieve optimal transmittance through spectral range from 340 to 750 nm (nanometers) — absorbance ±1%. Optical path 10 mm. Non-optical walls with special grooves for gripping and to avoid location errors. Dust-proof packing in special stackable trays made of expanded polystyrene. Each tray with cover holds 100 cuvettes, stacked 500 per case.