OTTO Excavator Parts Nkr55 4Jb1 Thermostat Tube 8970643080 897064-3080 8-97064308-0 For Isuzu The OTTO Excavator Parts NKR55 4JB1 Thermostat Tube, with part number 8970643080, is designed for Isuzu engines. This component facilitates the proper flow and regulation of coolant within the engine, ensuring optimal temperature control for efficient performance.