From Yale, the PM444 Door Security Bolt is designed to add extra protection to your home with a concealed, mortice-fixed fit. Installed into the door, it uses a bolt that throws into the door frame to help reinforce security where it matters most. Operation is key-controlled, using the supplied key, making it a practical choice for customers who want a straightforward way to increase door security without visible external hardware. Key features - Concealed, mortice-fixed door security bolt - Bolt throws into the door frame - Key-operated design - Supplied with a key - Model number: PM444 Please note: Colours shown are as accurate as possible, though may vary slightly depending on your screen settings.