Set of 4 coils. Dinan Ignition Coils are designed to be a direct plug-and-play replacement, or upgrade, to factory coils and provide greater energy output. With up to 10% more energy output than stock you are ensured a stronger and more consistent spark. Whether you are replacing dilapidated coils that are causing sluggish acceleration and/or misfires or simply upgrading for a more reliable and consistent spark your ignition system will be more efficient with a new set of Dinan coils. For those that like to showcase engine modifications they even come in a variety of unique housing colors to choose from for that personalized touch! The N series style coil applies to the following engines: M54*, S54, N14, N18, N20, N26, N52, N54, N55, N62, N63*, N73, N74, S55 and S63*. Compatible OEM Part #Cross Reference: 12138616153, 12138647689, 12138611236, 12138657273, 12120039634, 12120039664, 12130148594, 12131712219, 12137575010, 12137594596, 12137594937, 12137594938 and 02215044708. *M54: Some M54 applications split coil styles between M or N depending on vehicle production date. Cars produced up to 09/2002 will use the M series style coil whereas vehicles produced after 09/2002 will use N series style coils. Please visually compare / verify correct coil prior to purchase. *N63/S63: Some N63/S63 applications may require a minor modification (removal) of a small molding rib below the connector for proper fitment (~MY2016+). See FAQ under the Tech Resources section below to determine if your vehicle would require this modification for fitment. Once modified the coils are not returnable so please do so at your own risk. Viability of getting the mold changed so modification is unneccesary for future production shipments is under investigation.