Features: Provide safety measures to effectively prevent children from accidentally opening Window. Make of Aluminum alloy materials, strong, enduring, rustproof, and not easily deformed. Long/short designs, suitable for various size of Window. Easy to install, just locking it in the appropriate position. Window Lock is suitable for sliding window, sliding door and vertical window. Specifications: Materials: Aluminum Alloy Style: Silver 10mm short/Black 10mm short/Silver 16mm short/Black 16mm short/Silver 10mm long/Black 10mm long/Silver 16mm long/Black 16mm long/limit adjustable 16mm short suitable for track thickness: 1-10mm/0.04-0.39inch 10mm short suitable for track thickness: 1-16mm/0.04-0.63inch 16mm long suitable for track thickness: 1-10mm/0.04-0.39inch 10mm long suitable for track thickness: 1-16mm/0.04-0.63inch Package Includes: 8Pcs Sliding Window Lock/4Pcs Limit Adjustable Lock note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.