The Level Bolt is an invisible smart door lock that can be installed in a door within just a few minutes. This process replaces the original bolt while continuing to use existing covers, thus retaining the integrity of the building. After installation, all the advantages of the smart lock can be utilised, e.g. using a smartphone to unlock access for friends and family, allowing the user to keep track at all times of who has visited. The high-quality and durable lock can no longer be seen after installation, but does its job efficiently and offers considerable benefits.