Upgrade your ISUZU NPR, NPR-HD, NRR, or NQR with this set of 4 premium glow plugs designed specifically for 4HK1 5.2L engines from 2005-2015 models. These heavy-duty glow plugs feature robust steel construction with precision threading and optimal heat resistance for reliable cold starts and improved engine performance. The durable design includes a specialized heating element that provides quick pre-heating and maintains consistent temperature for smooth diesel engine operation. Each glow plug is manufactured to exact specifications to ensure proper fit and function, making them ideal for both maintenance replacement and performance enhancement. Perfect for fleet maintenance or individual truck owners looking to maintain their vehicle's starting reliability in all weather conditions.