If you have never seen the series this is a recreation of one of the propaganda posters trying to convince us that the alien "visitors" were our friends.
SPOILER ALERT: they were not.
Printed onto sheet aluminium (similar to what a road traffic sign is made from) and available in 3 size.s: A4, A5 and A6. The technique makes the print completely waterproof. Comes with 4 adhesive stickers which will adhere the sign to almost any surface.