what is this thing was on trailing sparkplugs

 

whats under it?. is it a normal plug is is that rotary plug.. cant think of the name

 

Looks like a pug that would sit near flush with the rotor housing. Never seen one like that though. Looks like someone liked the idea of one spark plug per rotor. Anyone else?

 

sits on top of standard plug came from 13b re motor

 

Your multiple bumps have been deleted. Bumps are forbidden in the 2nd gen technical section.

Looks like a cool cap, but it is hard to tell in the picture. Commonly used to reduce the possibility of detonation or pre-ignition on the trailing plugs, but at the cost of fuel economy on engines that run way warm.