This is one of the coolest features we have. It is a viewing window that mounts on the side of the kiln. It is made of quartz so it can hold up to the heat. We drill a hole in the brick and then carve it out on the inside to give you a wider viewing area. With the View Window you no longer need to lift the lid to see if your piece slumped just right. plus, it’s just really cool to look into the kiln while it is firing. We do recommend you wear protective glasses such as the ones that flameworkers or welders use.