HPD is an abbreviation used to describe the type of driver used within a model, in this instance it would refer to the High-Performance Dual.
The HPD drivers were only used for a limited run between 1974 and 1978, however, our current legacy range are modelled after the original drivers used within the Arden, Cheviot and Eaton of that time. The below models would have utilised an HPD Driver:
- Mansfield 12
- Mansfield 15