EUAS II FOR A CUSTOM FIT, NOT TOO TIGHT, NOT TOO LOOSE, JUST RIGHT! #snakedrsmartstrap How to use: Check to see if you have an NFC Enabled Phone... For Android, Blackberry and Windows devices you will find many applications on Google Play. We use NFC Tools Pro and NFC Tasks: The NFC antenna is on some devices is located on the battery for some devices and may not be present on replacement batteries. For iPhone 7 to X running IOS-11+ you can launch from the black disc, but you will have to use an application such as PROX NFC TAG that you can find on the Apple app store.