The Genuine ACDelco 4 Piece R44LTSM6 Iridium Spark Plugs are direct replacement spark plugs designed for GMC, Chevy, Hummer, and Buick vehicles. With the OE/OEM Part Number R44LTSM6 and 19355206, these spark plugs provide high-quality performance and durability. The brand new and high-quality surface finish ensures reliable ignition, while the iridium construction offers improved reliability and efficiency. Ideal for gasoline vehicles, these spark plugs are a crucial component for maintaining optimal engine performance and efficiency.