Which hard drive for LG TV?

[Flummingbird]

I know there's a good chance I won't get any replies, but...

I have an LG smart tv and want to buy a hard drive to attach so I can record programs. I can't see anything in any literature saying what kind or any spec etc that I need... do you know if I can just buy any external hard drive and use it?

I don't want to spend £40 on one and it's not right but I can't take it back as it's been opened/used!

[Flummingbird]

Hopeful bump for the evening crowd...?