Window rack bolts are an ideal way to increase security on timber windows. They are morticed into the window and operated by a spline key that throws the bolt into the frame. For optimum security it is recommended that the bolts are fitted to the top and the bottom of the window. Extra security 42mm length Used with spline key Fixings included" Case Depth mm: N/A Case Dia. mm: N/A Backset mm: 21 Bolt Dia. mm: 13 Bolt Throw mm: 11 Finish: White Material: Steel