The general purpose of these designs are described in “3D Printed UV-vis Cuvette Adapter for Low Cost and Versatile Spectroscopic Experiments”, which is published in the open access journal ACS Omega. Link to publication: http://pubs.acs.org/doi/abs/10.1021/acsomega.7b01310 This particular part is meant to mimic traditional quartz and glass UV-Vis Spectrometer cuvettes. In this design, we have a path length of 7 mm. This cuvette can be used in most standard UV-vis spectrometers. We recommend printing this design with a black filament to reduce the amount of light scattering. An instructional video to assemble the spectrometer is shown below with the materials used listed. Either quartz or glass windows can be used depending on the spectral range needed of the cuvette. https://www.youtube.com/watch?v=idU-oGBcP1k