These simple, reliable locks grip onto your window or door tracks to bolt them shut—keeping you and your family safe and secure. These sliding window security locks feature adjustable screws for varying window thicknesses, so you can use them to lock just about any window, whether horizontal or vertical design. Also great for securely locking sliding patio doors, the super-strong sliding window locks are easy to install and remove. Each 7/16" x 13/16" sliding glass window locks fit tracks up to 1/4" thick, twisting into place to secure anything narrower than 1/4". Set of 2 sliding window stopper.