What kind / type / model relay is this?
It's a small power relay (probably >2A) with a DC coil. You can apply voltage to it from a lab supply and figure out the proper coil voltage. It will probably pull in around 60% of rated voltage. Wild guess, 24VDC or possibly 12VDC coil. 

I would not suggest using it for anything serious without a cover-too easy for crud to get into the contacts.