Kensington BungeeAir Power Wireless Security Tether iPhone 4/4S

BungeeAir™ Power is the ultimate 3-in-1 accessory for your iPhone 4, featuring a wireless "invisible leash" (the so-called "Security Tether"), battery, and case. Simply attach the BungeeAir™ tag to your keychain or wallet to protect against losing your iPhone. If the distance between you and your iPhone becomes too great, the iPhone's display will automatically lock, and the BungeeAir™ tag will receive a warning notification. You can customize the security settings with a convenient app and even use the BungeeAir™ tag to locate your keychain if you misplace it.