The relay shown is a White Rodgers 586. Here is the manufacturers web page and spec sheets

http://www.white-rodgers.com/wrdhom/common/ptech/relays/relay_06.htm

http://www.white-rodgers.com/wrdhom/pdfs/sell_sheets/R-4005web.pdf

However I would NOT use it as a battery contactor as it will ultimately fail due to the high in-rush current of a starter will eventually carbon arc the contacts. A battery disconnect would be a better choice for the application described. You could always use two or more, however that would be pricey.

On another note, the prices from wiringproducts are too high, even higher than McMaster Carr (scroll to bottom - pn 7995k31 at $45.16). This relay is the most common starter relay for every diesel engine made today. It is the relay used as the pilot for the starter's solenoid. Can be obtained for about $35 at any Diesel Repair facility.

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me