The master lock indoor bluetooth padlock is opened via your smart phone it allows you to share access with friends family or even contractors without jeopardising your security you have the option to give permanent access restricted time access or even a 1 time entry code if you wish to give someone access and they dont have a smart phone you can give them a 1 time directional access code if your phone battery dies then you can use a directional combination to access your property the padlock