"热型火花塞" can be translated as "hot-type spark plug" in English.
Here, "热型" (rè xíng) means "hot-type" or "high-heat-range," indicating that this type of spark plug is designed to operate effectively at higher temperatures, often used in engines that run cooler or require a spark plug with a higher heat dissipation capacity to prevent pre-ignition. "火花塞" (huǒ huā sāi) translates directly to "spark plug."