Some important things you need when conducting the process of glass fusing is a pyrometer. What is a pyrometer? It tells you the temperature inside the kiln. Although it does not tell you the temperature of the glass, the air temperature gives the general temperature of your glass.
If you do not know what the temperature is inside, you do not have a clue about what happened in your glass. Every kiln 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 kilns do not have a display window, and it was fine for smelting. If you do not have a pyrometer, then it is a must to have a window so you can at least see what's going on inside the kiln. But, this kiln did have a peephole, which is located at the top of the kiln.
A kiln shelf is not provided for this kiln. A kiln shelf does not need to do glass fusing, but it is very helpful to have air circulation around your glass pieces. Air circulation helps to ensure that your glass is heating at an even temperature.
Kiln had a digital control button. It is fantastic, but when using the digital keys, you must constantly observe your pieces to make sure to get the desired effect. When teaching a classroom full of students, there is no time to stand oversees a furnace.