This web site has been designed to be as accessible as possible and compatible with the types of adaptive technology used by people with special needs, including screen readers.

Font Size

This website has been designed so that you can alter the text size for improved visibility. The method for changing font sizes differs depending on which web browser you are using. Consult your browser help for more information.

Navigating this Website

The pages have been laid out to be consistent throughout the web site, making navigation simple and intuitive. You’ll find links to the main sections on the top menu, links to the product categories and groups on the left hand side. Additional text links are available at the bottom of the page to the general information pages.


This site has been designed in accordance with UK government standards on web design, the published standards of the World Wide Web Consortium (W3C). If you experience any difficulties using our website please let us know by emailing us at