Some important things you need when performing the glass melting process is a pyrometer. What is a pyrometer? It tells you the temperature inside the oven. Although it does not tell you the temperature of the glass, the air temperature gives an overall temperature of your glass.
If you don't know what the inside temperature is, you have no idea what's going on in your glass. Each oven is different and unique. You may read more about it in the Beginners Guide to Kiln-Formed Glass by Brenda Griffith.
There was no viewing window. Most ovens don't have window screens, and it's good to meet. If you don't have a pyrometer, a window is a must so you can at least see what's going on inside the oven. But, it does have a pit oven, which is located on top of the oven.
A shelf is not provided for this oven. An oven rack does not need to fuse glass, but it is very useful to have air circulation around its glass pieces. Air circulation helps ensure that your glass is heated to a uniform temperature.
The oven had a digital control button. This is great, but when you use the digital keys, you should continue to look at your pieces to ensure you get the desired effect. When taught in a classroom full of students, there is no time to supervise the oven.