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 30 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 (post-printing) 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