This fastener comes as a four piece sash window lock/fastener, which combines into two components - one for each half of the sash window. The item is in two halves, with one attaching by means of screws to each section of the window at the horizontal meeting of the two upper and lower part. The twist arm features can be used for closing the window and also for locking the sash windows into a secure position by tightening the knurled knob.

Dimensions: 45mm by 19mm width for the base, this screws to the wooden frame, and the protruding screw length is maximum 65mm.