Screamin' eagle spark plugs

I have the stage 1 done to my '06 XL1200R, it's now fitted with SE EX12S plugs, instead of the factory fitted ones. What is the difference between these plugs?

I also note that HD sell an SE EX12P spark plug. How is this different to the EX12S, and can the SE EX12P be used safely instead of the EX12S?

[woody's dyna]

Supposingly the Screaming eagle plugs suppose to be a performance spark-plug. For stock or high-performance use. The patented split V electrode resists fouling (but also sold under another name 'splitfire').

The Screaming eagles EX12S is basically for stock and modified engines such as performance carbs, air cleaners, camshafts, exhaust systems in conjunction with standard compression ratios.

The Screaming eagle plugs EX12P is for high performance engines which may include all the above mods inconjunction with higher than stock compression ratios or engines used for racing applications.

I used the EX12S for a few years but went back to NGK standard plugs.