noun which may take the genitive case particle 'no'
non-standard
Used to describe something that does not conform to a standard, norm, or typical specification. Often appears in technical or formal contexts.
この装置は非標準の部品を使っている。
This device uses non-standard parts.
非標準的な方法で問題を解決した。
We solved the problem using a non-standard method.
規格外 also means 'non-standard' but often implies something outside official specifications or regulations, with a nuance of being substandard or not meeting requirements.
Compound of 非 (hi, 'non-') and 標準 (hyōjun, 'standard'). The prefix 非 is a common Sino-Japanese negating element.