Guide · · 3 min read
How to fit a SureFlap in glass or through a wall: adaptor, tunnel extenders and the hole sizes
Out of the box the SureFlap fits a door. Glass and walls need one or two extra parts and the right hole size. Here is exactly what to buy and what the glazier does.
By the Pet-Tek International team, Auckland — designers of Catwalk® and Dogwalk® since 1999.
The SureFlap Microchip Cat Flap is designed around a rectangular hole in a door. New Zealand cats mostly leave through glass, and quite a few through a wall, so here is how both are done — the parts, the sizes, and the order of work.
Glass: windows, glass doors and ranch sliders
Parts
SUR001 flap plus the GMA001WT2 mounting adaptor. The adaptor is a round white frame that clamps either side of the pane and gives the flap a flat face to screw to; nothing is fixed to the glass itself. In a double-glazed unit, add one TUN001WT2 tunnel extender so the flap’s tunnel reaches through the thicker pane.
What the glazier does
- Marks a 212 mm round hole with its bottom edge about 100–150 mm above the floor, a safe distance from the edge of the pane and clear of a slider’s handle side.
- Single glazing: cuts it in place with a core drill. Double glazing or toughened: orders a new sealed unit with the hole made in both sheets, then swaps it into the existing frame a week or two later.
Give the glazier the number 212 mm and the drawing on the product page. Our glass installation guide covers the general steps and costs.
What you do
- Clip the two halves of the adaptor either side of the hole and tighten them together.
- Fit the flap’s outer frame into the adaptor from outside, inner frame from inside, and screw them together.
- Insert four AA batteries, register the cat, test the lock dial.
The “fitting it in glass” video is on the product page.
Walls and thick doors
Parts
The flap’s own tunnel is 70 mm. For anything thicker, TUN001WT2 extenders clip onto the outer frame at 50 mm each. Thickness minus 70, divided by 50, rounded up: a 90 mm framed wall needs one; a 220 mm block wall needs three. The last one can be trimmed with a fine saw to finish flush.
Steps
- Find the studs; the 165 × 171 mm cut-out has to sit between them. Mark it with the bottom edge at the cat’s belly height, 100–150 mm up.
- Cut through both skins with a jigsaw (masonry: a builder cuts and lines the opening).
- Clip the extenders onto the outer frame, push the assembly through from outside, screw the inner frame on from inside. The extenders line the hole so the cat walks through a smooth white tunnel.
- Outside wall: flash the top of the opening and run silicone under the outer frame.
Existing round hole from an old cat door
Replacing a worn-out door that left a round hole? The GMA001WT2 covers anything from 212 to 260 mm in a door, wall or glass, and the SureFlap mounts to it as if the hole were new. Measure the hole first; if it is bigger than 260 mm, a Catwalk® Standard (245 mm) or Maxi (267 mm) may be the better match.
Not for the Pet Door
The GMA101WT2 adaptor and TUN101WT2 extender are the larger SureFlap Pet Door parts (294–320 mm hole, 207 × 234 mm cut-out). They do not fit the Cat Flap; we stock them for owners who already have that model.
Order checklist
| Situation | Cart |
|---|---|
| Single-glazed window or slider | SUR001 + GMA001WT2 |
| Double-glazed door | SUR001 + GMA001WT2 + 1 × TUN001WT2 |
| 90–120 mm framed wall | SUR001 + 1 × TUN001WT2 |
| Block or brick wall ~220 mm | SUR001 + 3 × TUN001WT2 |
All in stock in Auckland; free shipping over NZ$250. Still unsure? Email a photo of the door or wall to info@petnest.co.nz.
Quick answers
Can a SureFlap be fitted in a glass door?
Yes. A glazier cuts a 212 mm round hole in single glazing, or supplies a new double-glazed pane with the hole made, and the SureFlap mounts through the GMA001WT2 mounting adaptor, which clamps either side of the pane.
How do you fit a SureFlap through a wall?
Cut the 165 × 171 mm opening through the wall, clip TUN001WT2 tunnel extenders onto the flap's outer frame — 50 mm each — until the tunnel reaches the far face, push it through and screw the inner frame on. The extenders line the hole.
What size hole does a SureFlap need in glass?
212 mm round for the Microchip Cat Flap with its adaptor. The adaptor also covers an existing round hole from 212 to 260 mm. The larger SureFlap Pet Door uses the GMA101WT2 adaptor and a 294–320 mm hole.
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