Longest 10baseT length?

Guys, What is the longest distance you can run a pc from on a 10baseT network? I have a client that has a warehouse say 400 feet away from the switch he's using and he wants to slap a PC there and run it on his network.

So what do I need? One long assed cable? Shielded? Unshielded? What?

I am pretty sure 100M, so 300 feet or so. You could get another switch to bridge the two. You could also try to use fibre, but then you'd need another switch anyway.

normally it is advised not to go over 100m. But if you use a good unshielded twisted pair cat5 cable you can probably go to 400 ft.
I've pushed the distance and it seems to work fine.