Repl. for OEM #4 (H8C). 14mm threaded. 11.2mm reach. Used with 21mm socket wrench. NGK copper core V-Power spark plugs feature a specially designed v-groove center electrode, improving ignitability and reducing quenching. The 98% pure copper core delivers increased heat dissipation for more reliable starts and reduced risk of overheating. - Cold-rolled threads prevent cross-threading and damage to cylinder heads. - Trivalent plating eliminates need for anti-seize. - High-grade alumina silicate ceramic.

Fits: > 57-78 XL (NU)