Smurf051

A guy was selling parts to me for cheap and he mentioned a "stall converter". I would like to sell it, if anyone was looking for one because I have no use for it now, I'd have to take out the transmission or engine. I'm new to mustangs but I have a general idea on how things work but I don't know how one of these really works or how it benefits the car. It's for a C4 transmission and stalls at 1800.