Security: to prevent any break-ins, this device locks the window when it is ajar and renews the air inside. Appearance: professional surface treatment, solid, compact and aesthetic. Using high quality materials, easy to open, suitable for most plastic, steel and alloy windows. Multi-function - These locks work well on most wood, glass, plastic and metal surfaces . You can secure your sliding doors, porch, closet, shower, storage room and entertainment center, as well as your sliding windows. Your child will be able to explore without injury. Premium Quality: Our sliding door lock is made of durable metal reinforced with rubber. Our sliding door locks limit and lock the opening of sliding doors and windows so your child stays safe inside.