It’s an indoor padlock that works with your smartphones to unlock it using a smart app. You can control this gadget without using phone by entering directional code. No need to carry keys for your lock as your smartphone will become your handy key lock. You can share access of this lock with others and enjoy maximum security, durability and reliability with the anti shim technology. With this gadget you can always track each and every locking and unlocking activity from anywhere. This master lock with backup feature is priced at around 49$.