High-performance NGK IRIDIUM CR8HIX spark plug. 10mm thread, 1/2" reach, 5/8" hex, gasket seat, resistor plug. Fits Zenoah G230RC / G260RC / G231PUH / G260PUH / G260PU / G231PUM / G260PUM engines. Also fits Chung Yang CY23RC / CY26RC / CY27RC / CY29RC / GP290 engines. Features ultra-fine .6mm center electrode. Terminal nut included. For: Lower fuel consumption, longer engine life, smoother engine operation, and improved ignition efficiency.