Look for a really really light grey/yellow print in a really big font (so big you don't notice it until its pointed out to you) on the white sticker with all sorts of safety text on it. The stickers say something like M 90 or SA 95. I felt real foolish once I saw it, because I spent many minutes trying to tear the thing apart to find the sticker, and it was right there in front of me the whole time.