VRDP05500 | Goods supplied for the use of disabled people [item 2]: are products suitable for a disabled person’s needs eligible for VAT relief?
From HM Revenue & Customs · VAT Relief for Disabled People Manual
A person with a disability may select a particular model or product which best suits their needs. It may:
be more robust;
be made of particular materials; or
have additional features,
which facilitates its use by a person with a disability. This may sometimes make the product more expensive than the standard model, but it does not of itself make the product zero-rated for VAT purposes.