I'm getting rid of these because I was made to collect nearly 30 of them for work, but I only need two. Simply put, they are the cores of receipt rolls. *Also listed on other flea market sites, so early closure is possible.* Size: Length: 7.9 cm Width: 1.8 cm Thickness: 3 mm They are quite hard. If you accidentally step on one barefoot, you'll be writhing in agony for about two minutes. *The card in the photo is for size comparison only.*