High-Security Sliding Window Lock - 3-Second Installation by Pro Tools Instantly lock sliding windows and doors - no drilling or tools needed Place on window or door track & tighten thumb screw; lock shut or allow partial opening Prevents window from being forced or pried open from outside; easy removal and reusable Fits most vertical or horizontal sliding windows & many sliding doors to 1/4" track-rim width Heavy-duty extruded aluminum won't rust or corrode