This glass of mika can be placed in the oven door to close the hole.
3 x 3cm
To install the mika window you will need a screwdriver.
Carefully remove the screws slightly but not completely. Just enough to lower the window behind the metal.
The window can now be lowered between the door and the metal plate while holding your finger in the hole, so you can lower it so that it does not fall.
Keep the glass on its place by gently pressing the window in the hole so that it stays in place and carefully tighten the screws.
CAUTION: Do not over tighten the screws. Fixed is fixed, because it is located only ceramic material in the door.