NGK PTR5D-13 / PTR5D13 / 6644 Laser Platinum Spark Plug Replaces OE029 RES9PYP4 PT16EPR-L13 (6644 )OE Platinum spark plugs offer high ignitability & longer service life. Dual platinum surfaces ensure a slow wear rate providing stable idle, superior anti-fouling, enhanced fuel efficiency & lower emissions. Laser-welded platinum center electrode tip Platinum disc welded to backside of ground electrode provides long life Trivalent metal plating provides superior anti-corrosion & anti-seizing properties Faster starts & quicker acceleration Better fuel economy & lower emissions Best platinum spark plug available OEM-approved design BOX DIMENSIONSHeight (mm): 85 Width (mm): 24 Length (mm): 22 If you are unsure as to whether this is the correct part for your vehicle, please don't hesitate to contact us. Alternatively please use the cross reference table above.