Compounds are provided that act as potent antagonists of the CCR1 receptor, and have in vivo anti-inflammatory activity. The cylinder head gasket may be made from metal or a composite material, and is disposed between a cylinder head and a cylinder block. The first operational amplifier is switchable over between two specified voltages and the second operational amplifier is operable to adjust a specified constant voltage at the connecting point between the resistor and the sensor, and the output of the second operational amplifier is connected to an input of a comparator whose other input is switchable over between two specified voltages. The activator may be an alkyl-substituted cycloalkane, a soy oil, an alkyl soyate, or combination thereof.