The tags can be attached to different items with a keychain for easy tracking. The included case is IP67 waterproof, protecting the tags from wear and rain, extending the life of the tags. No subscription and monthly fees are required for this item tracker. It is only compatible with iOS devices ( etc.), not for Android. Easy to carry. Perfect for tracking cars or bikes in parking lots; perfect for travelers to track their luggage or friends' locations; perfect for forgetful people to quickly find their personal belongings such as keys, wallets, backpacks, handbags, etc. Attach these tracker tags to anything you need to keep an eye on. When your item is out of Bluetooth range, the item locator will send you a reminder so you can go back and retrieve it.