Each order = 5 sheets (40 removable stickers) featuring 8 Pi Symbol Stickers (4 are 2.5 cm length, 4 are 1.5cm length.) Great for cards, envelopes, school projects, laptops, windows, appliances etc. Stickers are acid, PVC and phthalate free. The adhesive is mild allowing you to easily remove the stickers without any damage or leftover residue. After being applied, the bond will strengthen over time. Not recommended for outdoor use.