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 10 mm. This adapter is meant to hold a planar and transparent working electrode like ITO or FTO. A reference electrode can be placed in the adjacent hole and the counter electrode placed in the second hole. Note that the counter electrode hole is connected to the main electrolyte compartment via a tunnel running underneath. A peltier-thermoelectric module (with a hole) can be used to control the temperature (https://tetech.com/peltier-thermoelectric-cooler-modules/round-with-center-hole/). Additionally, there is a protected inlet port to enable the electrolyte to be flushed with a gas without generating intense bubbles at the electrode surface. This cuvette can be used in most research grade 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://youtu.be/idU-oGBcP1k