14mm Thread - .460 in Reach - Tapered Seat - 4 Pack;Shorty Spark Plugs For Tubular Exhaust Headers; Eliminates Dimpling Headers For Added Clearance; Improves Spark Plug Access To Fit Socket Or Wrench; Shorter Overall Plug Length Vs. OE Style Plug; Copper Core Center Electrode; Projected Tip; Helps Eliminate Burned Spark Plug Boots;