This book-shaped NFC tag keychain is perfect for tech-savvy customers and book lovers alike. Sold blank and unprogrammed, it's ready for your customers to write their own URL, app link, or digital experience using any free NFC app. Lightweight and giftable, it's a fun, interactive item that works for authors, small biz owners, or anyone who loves clever tech. -Packaging: Each keychain comes in a protective sleeve with programming instructions printed on a small card. -Note for Buyers: Compatible with most modern smartphones (Ios 7 and up, and Android 2019+) Important note when ordering: Green= Mint, Brown=Nude (Photos below)