Narrow Lock Frame Design：Keeps the chain in place when the doorstop isn't in use, door and frame damage from a hanging chain. Strong and heavy duty, longer service life. Ideal for front doors, apartment doors, hotel rooms, and even sliding glass patio doors, additional security for your home or office doors are within reach! All installation hardwares are included in the package,so you can mount it easily. Chain Gate Guard allows you to partially open the door to identify visitors or receive packages, and to provide reliable protection against intruders. Door chain lock allows you to identify visitors before fully opening the door, providing additional security and preventing intruders from easily entering your property.