How can I correct OTG cable for my Seagate2TB to connect to my Samsung Galaxy Tab2 9.7?

[AC Question]

need the correct OTG cable for my seagate2TB to connect to my samsung gaxley tab29.7

I have a new Samsung galaxy tab2 9.7 tablet and a Seagate 2TB external hard drive..want to be able to back up tablet to hard drive which 2.0 3.0 otg cable do I need and where to purchase it?