This works fine on the new white Tablo. 5Tb for about $100 and probably more than you will ever need unless you keep complete series of shows.
BRAND NAME: Seagate
PRODUCT NAME: Backup Plus Slim
SIZE: 1 TB
LINK: Seagate STHN1000400 1TB Backup Plus Slim Portable Drive USB 3.0, Black - Walmart.com
COMMENTS: Has been working flawlessly for two years.