Our Mifare Classic� 1K NXP EV1 27mm circular stickers are designed with high-quality materials and have a no-battery design, which means they can be read an infinite number of times. These stickers can be easily attached to phone cases, wallets, and cards, enabling access control capabilities with a read range of up to 10cm. Product Details:Sold in packs of 100Self-adhesive and waterproofOperates at 13.56MHz Frequency