The Modine 3H0400780003 Limit Switch safeguards the unit against damage by sensing abnormal temperature changes or pressure conditions and then shutting down the unit if necessary. Features. Real OEM buttons and switches support efficient HVAC operation for ideal indoor climate control. Genuine OEMSpecifications. Key Information Auto Reset, L22040F. Length 6.95 in. / 17.65 cm. Width 6.85 in. / 17.40 cm. Height 2 in. / 5.08 cm