The Mifare Ultralight C hold 192 bytes of data, with approximately 137 bytes of writable space -  plenty for most tech enthusiasts. Toggle WiFi and Bluetooth and leave this sticker in your car  to automatically enable Bluetooth and disable WiFi (to help save battery) when tapped - you even launch your favorite music app, all from the same sticker! Works with most Tasker tasks as well.This NFC inlay comes in a 30mm clear sticker. These labels have a readable distance of up to 4 cm (typically around 2 cm dependent upon the antenna geometry) and a write cycle of around 10,000. These stickers work great with ALL NFC enabled Android and Blackberry phones. Just install an NFC writer app and you're ready to read and write tags - And you can Write, Rewrite and Reformat these tags as often as you like! These stickers are not intended for outdoor use or use on metal surfaces.