Masterbolt is a outboard door that provides additional protection in seconds. Quick installation on any door will unforeseen visitors from entering the room. This construct is for people who travel often and stay in short-run rentals so much as hotels, hostels, or Airbnbs. Masterbolt is also to send to your son or daughter currently living in the dorms, or in their apartments in the city. it to family and friends who will be traveling this summer for more peace of mind. Masterbolt wherever you go for additional safety, security, and privacy.