Cole Hersee Marine Engine Warning Kit M-40177-BP Includes warning buzzer, oil pressure switch and temperature switch. Protects engines from the two major causes of damage: no lubrication and overheating. Warning buzzer sounds when engine oil pressure is too low and/or engine coolant temperature is too high. For inboard and I/O engines. 12VDC. Incorporates #4099 buzzer. Oil pressure switch #8606 operates at 3 to 7 psi. Temperature switch #84251 operates at 200 F. Installation instructions included.