These are a set of seven posters (kilometer, hectometer, dekameter, meters, decimeter, centimeter, and millimeter) - one set in color, the other in black and white.
Print, laminate and hang. These are a great reference for your students when they are tackling metric conversions.
I have also used them during whole group instruction - I pass out all seven posters and then have the seven students get themselves in the correct order at the front of the room. The students that are seated can help if they are having difficulty. Repeat until everyone has had a turn.