This is a "W Sash Lock, Set of 2". It serves four functions: window security, ventilation lock, screen door lock, and child safety. The first lock provides security when the window is completely closed, and the second lock allows for ventilation when the window is open. It can also be attached to screen doors and helps prevent falls for small children. Installation is easy, just stick it on with double-sided tape. With the W lock's four functions, you can ensure ventilation, security, and screen door safety. Thank you for viewing. This is a new, unused item, but it has been stored. Please check the images before purchasing.