cardinal gates child proof ultimate door guardian door lock, 2-pack cardinal gates the ultimate door guardian for when you need a child safety lock that will work with most any door. created by and manufactured by the same people that invented the original door guardian, this child safety lock will work with either inward or outward swinging doors. it comes with two different receivers for the lock to fit into while engaged. there is also an optional safety insert and key for when your childproofing measures need to go an extra step. the ultimate door guardian installs quick and easy - all parts mount with very high bond tape and includes screws for additional strength. the installation options give the ability to attach to just about any door: metal, fiberglass, wood, even glass shower doors. the ultimate door guardian is installed high on the door and out of reach, ensuring that children cannot reach and unlock it. the lock is made of metal while the receivers and other parts are made of a lighter weight plastic. this child safety lock is a needed addition to childproofing your home.