Replacing an Existing Cat FlapUpdated 21 days ago

Already have a cat flap and want to upgrade to Flappie? In many cases, your existing hole can be reused — depending on its size and shape.

Glass installations (circular hole)

Flappie fits into circular glass holes between Ø 212 and 270 mm. Here's how common cat flap brands compare:

Previous cat flap	Typical hole diameter	Compatible with Flappie?
SureFlap Microchip Cat Flap	~212 mm	Yes — direct fit ✓
SureFlap DualScan	~212 mm	Yes — direct fit ✓
SureFlap Microchip Pet Door (large)	~262 mm	Yes — with mounting adapter ✓
PetSafe Microchip Cat Flap	~212 mm	Yes — direct fit ✓
PetSafe Petporte Smart Flap	~250 mm	Yes — with mounting adapter ✓
Older/generic cat flaps	varies	Measure your hole and check below

Quick rule: Measure your existing hole. If it's between 212 and 215 mm, Flappie fits directly. Between 215 and 270 mm, you need a mounting adapter →. Smaller than 212 mm or larger than 270 mm means the glass needs to be replaced.

Door/wall installations (rectangular hole)

For rectangular cut-outs, Flappie needs 173–210 mm (H) × 167–175 mm (W). If your existing cut-out is close to this range, you may be able to enlarge it slightly. If it's significantly larger, you'll need to reduce the opening (e.g., with a wooden filler panel) or cut a new one.

There is no mounting adapter for rectangular openings — the cut-out size must match the required range.

What about the tunnel?

If you're replacing a cat flap in a wall, you'll likely already have a tunnel through the wall. You can't reuse the old tunnel — but the hole itself should work. You'll need Flappie's own tunnel extensions → for the correct depth.

Not sure?

Take a photo of your current installation and measure the hole diameter (for glass) or height and width (for doors/walls). Send it to [email protected] and we'll tell you exactly what you need.

Questions? Write to [email protected] or use the chat in the bottom right — we're happy to help.

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