The Prime-Line U 9800 sliding window thumbscrew lock is the perfect solution to secure your slide window, preventing unauthorized entry and enhancing overall safety. Designed for easy use, this lock with thumbscrew can be quickly installed without any tools, making it a hassle-free way to secure your windows. Crafted from durable extruded aluminum with a sturdy steel thumbscrew, this thumbscrew window lock offers long-lasting strength for consistent performance in securing your windows. Compatible with older-style sliding window frames that are up to 3/16 inches thick, this window frame lock provides a tight fit for both horizontal and vertical sliding window systems. For further dimensional information, please see the line drawing.