not really sure they were given to me when I was helping a friend clear out a building. it looks like you just lay your item on it. there are three different pieces. fanned
saw a video on utube. it's a manual way (instead of digital exact) to put enough / approx amnt of postage. you place your item on the 1,2 or 3 pd stand (like pic above) until the stand is NOT flattened by your pkg.