Designed for cats up to 20 pounds, this convenient cat door safely allows cats to go outside, and return home, whenever they please. It easily installs into any standard-size window that measures 24-1/2 by 34 inches wide and opens vertically. The non-permanent door works great for apartments, condos, or homes because it can be removed at any time without any harm to the window. Other highlights include a secure weather-tight design that locks the unit in place for stability and a four-way locking cat flap, which allows for controlling the cat's access.