The practical demonstration of electrolysis is a foundational example of electrochemistry that is often introduced to students during secondary education. However, when students subsequently encounter solid polymer electrolytes, such as proton exchange membranes (PEM), they may experience confusion due to the added complexities. In this work, we aim to outline the working principles behind PEM electrolysis and present an educational device for use in the classroom as a demonstration or as part of an introductory undergraduate-level laboratory practical. The transparent cell design allows students to view inside the cell, enabling them to visually experience the occurring electrochemical phenomena. The detailed construction information is provided to allow for easy replication. Various pedagogical applications are highlighted, along with example worksheets for stimulating discussion around PEM electrolysis, a potentially transformative technology to drive forward the production of green sustainable hydrogen from renewable electricity.