The FOS550 is a high-security additional lock for windows and patio doors with two strong fixing points at top and bottom. The patented locking system provides the lock with extremely strong resistance to force and interference with the handle.
The particularly slim design means that the window lock FS0550 can be used on almost any windows and patio doors that open inwards, including most double windows with or without a mullion. The modern design of the additional lock with its elegant lines and slim, attractively shaped bolts looks good.
The window lock FOS550 operates in a simple and logical way. It is activated by means of the lockable window handle. Whenever the window is closed, the bolts at top and bottom are always extended and the window is secure. It's impossible to forget to lock it ever again.
Of course, this additional window lock has been tested and approved by the testing body of the insurance companies (VdS). Able to withstand a force of about one tonne.