Radiator Fan Temperature Detection Switch compatible with models requiring part numbers 27010-1249 and 27010-1304.Designed for use with EX250, 250R, ZZR250, GPX250R, ER500, ER5, EX400, and EX4.This switch monitors engine temperature and activates the radiator fan when preset thresholds are reached, helping maintain operating temperatures.Installs directly into the cooling system to ensure thermal management.Constructed to match specifications for proper fit and function. Compatibility Disclaimer: This is an aftermarket replacement part.Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.