Yeah, that's what was most useful about Indespension. It almost made up for them being more expensive than web rivals and them never honouring the club discount...
Have you replaced the cables before and do you still have the receipt? It should say what they are.
Indepsension website (and most others for that matter) good for identifying what you need as well.
If you have Knott brakes, I recently got stainless cables from Western Towing (Trailertek may also do them) for less than the price of mild steel ones from Indespension. I'll report back in 12 months as to whether they've lasted any longer!