Features: 100 percent brand new and high qualityHigh-quality materials: use aluminum alloy material, stable and durable.Punch-free installation: Each lock is provided with a key, slowly turning the foremost during the hole, solely deserve to use the most important to control, no extra installation tools.Controllable width: freely control the window width to forestall kids or pets from crawling out of the window.Necessary items: Fix home windows to prevent teenagers from falling and prevent thieves.Suitable for families, hotels, schools, kindergartens, etc.Specification: Material: Aluminum AlloySingle Hole Wide Size: Approx. 2.3x2.3x2.9cm/0.91x0.91x1.14inchSingle Hole Narrow Size: Approx. 2.3x1.8x2.9cm/0.91x0.71x1.14inchDouble Hole Wide Size: Approx. 2.3x2.3x5.98cm/0.91x0.91x2.35inchTwo-hole Narrow Size: Approx. 2.3x1.8x5.98cm/0.91x0.71x2.35inchStyle upgrade/Suitable for trackUpgrade single gap slim version:Track thickness 1-10mmUpgrade single hole extensive style:Track thickness 10-16mmUpgrade the narrow double gap model:Track thickness 1-10mmUpgrade double hole broad style:Track thickness 10-16mmPackage Includes: 6pcs Window Safety Lock(with Key)note: 1.Please enable 1-2cm mistakes due to handbook measurement, make sure that you don't intellect before you order.2.Due to the variation between assorted monitors, the picture might not reflect the actual colour of the item.