> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.onlycat.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# What are the dimensions of OnlyCat?

## Check the current installation guide before cutting

Use the maintained [Dimensions & Specs](https://www.onlycat.com/specs/), [door](https://www.onlycat.com/installation-guide-doors/), [wall](https://www.onlycat.com/installation-guide-walls/) or [glass installation guide](https://www.onlycat.com/installation-guide-glass/). Confirm the opening, material and adaptor before making permanent changes.

OnlyCat’s external tunnel measures **165 × 172 mm** (width × height). This is a product measurement: for the opening to cut, use the supplied frame or printable template and the current guide for your installation. The standard glass mounting adaptor suits a **212–260 mm** circular cutout; larger existing openings require confirmation of the appropriate mounting accessory.

For larger existing cutouts, such as those with a SureFlap Pet Door, we offer three large [mounting accessories](https://www.onlycat.com/store/glass-mounting-adaptor/) (Large Round, Large Square, and Large Squircle) to convert to OnlyCat.

For more detailed specifications, please visit our [Dimensions & Specs page](https://www.onlycat.com/specs/).




![](https://storage.crisp.chat/users/helpdesk/website/-/9/d/9/a/9d9a00682326c00/dimensions-full_s85tot.webp =924xauto)