OS SPEED edition of the P3 plug with 24k Gold coating. Developed as part of the 80th anniversary celebrations for OS
Features:

 
Easier to tune
 
More low-to-middle range power
 
Quicker throttle response
 
Faster acceleration
 
Better mileage
 
Crisper idling, with a difference you can hear
 
Increased longevity
 
Speed P3 ideal for ultra-hot applications;

The OS P3 Plug is well suited to a wide vareity of engines, specifically those OS based .21s such as V Spec and Later VZ-B and XZ-B as well as B2101 and B2102.