That is a plexiglass front panel, 4 screws remove it. I have one of these I am rebuilding, that panel is strange, its got a 1/2 gap between it and the grinder, so most of the beans fill it up but never come out. I guessing when its sitting on a counter they want the customer to see lots of beans. I plan on replacing mine with a flat piece of plexglass. The insides of these look like a tank, I believe they will last forever. They do not use sharp burrs to grind, it seems to crush the coffee if you look at the burrs. I never fix mine yet so I hope they do a good job grinding. The book says you can grind thousands of pounds before replacing burrs.