Specifications: Features: 1.Copper dissipates heat quicker, cooling the electrode and insulator tip. 2.Raised pre-ignition rating with high conduction copper and long nose insulator. 3.Each meets the requirements of high-performance engines. Specifications: Thread diameter: 14mm Thread reach: 9.5mm Seat type: flat Hex size: 19mm Tip configuration: projected Construction: Standard construction Terminal type: Removable New 4pcs/6pcs Torch Spark Plug L7RTC for Autolite XST2974 Bosch WSR6F Champion RCJ7Y Denso W22MPR-U NGK BPMR7A Gasoline Engine Fits for Engine 2500 3800 4500 5200 5800 MS170/MS180 MS230/MS250 MS380/MS381 MS660 MS070 137/142 365/372 268/272 PT350/360 TU26 34F 36F 40F-5 44F-5 Torch L7RTC replacement spark plugs: Autolite 2974 Autolite 2976 Autolite XST2974 Bosch WSR5F Bosch WSR6F Brisk PR15Y Champion 852 Champion 858 Champion CJ6Y Champion RCJ6Y Champion RCJ7Y Denso W22MPR-U NGK BPMR7A Please note: due to production series, the detailed colors may vary, but the performance is the same.