This sticker has a format of 29 cm x 29 cm and has the shape of a cross.
As a backglass sticker, you can attach it to your shop window or entrance door from the inside. He is deliberately removable, so they can "let him move".
Also, you do NOT have to register it as a "structural measure" or "structural change" at the Ordnungsamt or other official institutions or your landlord and have it approved, as is the case with "Aufglas stickers" in some cities and towns.
