HW is Allegion-specific nomenclature used when specifying hurricane rated devices and mullions that are for use in non-impact (Wind-Only) hurricane zones.  The devices may require special strikes, and mullions will require special a bottom fitting mounting package for these zones.  By specifying HW prefix, the customer will receive the correct components. This change became effective mid-2021.

HH device and mullion prefix is for the more stringent Wind and Impact hurricane zones. 

If application is unknown, specify HH prefix, which will satisfy both applications.