Note About the Replacement Door Fit for "OLD" Pet Eze Doors:
When Pet Safe bought Pet Eze they changed the frame design a little bit, and they no longer provide instructions on how to properly install these flaps in Pet Eze doors. If you get your flap and it appears to be about 1/4" too short, don't worry. It is the right flap. All that is needed is to pull the magnet bar up to hit the bottom of the flap.
Details
The NEW Pet Safe doors have a "floating magnet bar". The OLD Pet Eze have a manually adjusted bar. (The magnet bar is directly underneath the flap. Its magnets attract the magnets in the flap.) The magnet bar is about 1/2" wide and usually sticks up about 1/8" higher than the rest of the frame. (At first glance it looks like the frame is all one piece, but it isn't; the center part moves.) Over time, the manually adjusted bar drops too low.
Grasp the bar on the ends with a pair of pliers and wiggle it and pull it up. It will adjust up out of the frame where you can make it fit your new flap tightly.
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