This is a general purpose automotive change-over-relay with mounting bracket. It is the "Bosch Style 5 Pin Relay" used by the thousands in auto electric shops for years.
12 volt DC 30-40 amp, SPDT 5 terminals with resistor for voltage spike protection.
Please Note: These are not manufactured by Bosch, they are made by PICO, a long time provider of aftermarket automotive parts.
All prices are in USD.