What is the difference between ‘D’ and ‘W’ profile pales?

‘D’ profile pales (typically 3mm thick) and ‘W’ profile pales (typically 2mm thick) offer varying degrees of rigidity and physical deterrence tailored to different commercial security specifications.

‘W’ profiles tend to be used for high-security industrial and commercial sites.

‘D’ profiles tend to be used for medium-security site and frequently specified for schools and public parks.