CotsLab manufactures and develops a full range of laboratory use optical glass, quartz, NIR and sapphire cuvettes and cells. Custom design of cuvettes and cells in different sizes or materials. Our products range from all series cuvettes and flow cells and watch glasses to large, complex laboratory apparatus.Please note that this is a liquid calibration filter and does not come with the same Lifetime Warranty as Firefly's Solid State Standards. The Firefly liquid holmium filter must be recalibrated every year according to NIST guidelines