This is an automotive air conditioning trinary switch. In addition to high and low pressure cut-off, it can also trigger a cooling fan. Male R134a trinary high & low pressure switch, fan on at 227 PSIG, off at 185 PSIG. Low opens at 28 PSIG closes at 29 PSIG. High opens at 454 PSIG closes at 369 PSIG. Blue wires are fan trigger and black are for the compressor.
