Hey guys

Finally 60 pop on my warrior

I ask a guild, for an raid seet. They say, they are full of off warris and mt's, but they look for an offtank.
Here are my questions:
Whats exectly the job of an offtank in a 40 raid and what should i spec? Same spec as MT? Offspec (arms, fury)? and tank when needed?
What gear should i prefer? Tank gear? Dps gear?
Whats my job when 1/2 mts is enough?
Thanks for the answers
