ALL SPARK PLUGS ARE SOLD INDIVIDUALLY!! AUTOLITE SPARK PLUG 4163/4 COPPER 4163. The vendor part number is 4163. Read title carefully to know what you are getting. Here is the catalog descrion NOT the title?

• Copper-glass seal bonds insulator, terminal post center electrove together; assures full required voltage at spark gap; gas-tight seal (100% leak proof)
• Multi-rib insulator reduces dange of "flash-over"
• One-piece terminal post adds strength
• Resistor reduces radio frequency interference (RFI) and electrode erosion
• Cold-formed steel shell precision rolled threads
• Full copper core electrode provides better performance in all conditions