Connecting a hard drive via USB

[smmmokin]

See attached picture.

 

Bought this many years ago to use an SSD as an external. But now I want to connect some bigger drives with spinning plates but now I need power.

 

I have no clue what kind of power source to buy to plug into this thing. I have a box with all kinds of connectors but don't want to destroy anything. 

 

Question: what kind of power cord do I need? Or is there a better all in one adaptor I can buy that removes any kind of guessing?

 

EDIT: I have old power cables for external hard drives but all of them the plug is too large to fit into the power connector. 

[Kilrah]

If you have a record or can find what model this adapter is you can likely search for specs.

 

It'll likely need 12V for 3.5" drives. Easiest to make sure would be to use a multimeter to test continuity of the input plug to the 12V / GND SATA pins, if they're directly connected you'll know you can just use any 1A+ 12V adapter and the polarity.