Glass Cuvettes and Caps for Checker HC Colorimeters (set of 2) - Hanna Instruments When using a colorimeter or photometer it is important to use clean cuvettes that are free from scratches. Any discoloration or scratches will interfere with any optically based measurement. The HI731315 are the replacement glass cuvettes for the Checker HC Colorimeters. If you need extra cuvettes to test more samples or are looking to replace the cuvettes that came with your Checker, this set comes with two cuvettes with caps. The HI731315 are spare glass cuvettes and plastic caps used with the HI7XX Checker HC colorimeters. Each cuvette has a 10 ml level mark to measure the appropriate volume. The HI731315 includes 2 cuvettes and 2 caps. 10 ml level mark for adding correct volume. With extra cuvettes you can test more samples and average your results for the best accuracy. Replace scratched or discolored cuvettes.