A traditional Brighton pattern sash window sprung fastener for narrow stile window frames. Locking version. A classic method of fastening and locking sliding sash windows. To lock, pull the sprung toggle arm down and screw the knob into the keep. To unlock, unscrew the knob and the arm will automatically flip up to the vertical position allowing ample clearance between the moving sash windows. Available in an extensive range of finishes. Operating key WFKEY/4MMCP sold separately. Comes with a 10 year mechanical guarantee.