That is an extended reach plug similar to the Bosch W8DTC. It is not the best choice for the Water boxer. That large center electrode can add to the possibility of detonation and it is too close to the piston. The Bosch 7177 is considerably shorter close to the Bosch W8C. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dan N
Sent: Friday, February 19, 2016 9:41 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Tune Up Poll

I use NGK BP6ET - triple electrodes plugs - so no need to gap or regap