the dark Cat flap can be installed on the screen Note that this screen door itself does not contain a lattice, it is just a door frame, as it must be installed over the existing lattice. Novel design, high quality material, using roller movable door, easy to enter and exit, the bottom is equipped with suction cup iron positioning, two-way entry and exit, can also set the direction entry and exit, suitable for all kinds of dogs! Product name: pet window screen door. Product material: 2-way PP plastic inside and outside at will Product size: Outer frame size: length 45.5 x width 35.5 x height 2cm (suitable for dogs and cats of all sizes) Inner door size: length 40 x width 30cm