Southwest is on their own site so you always have to check it.

Info on the smaller planes is handy to have. I noticed a lot of sites list the type of aircraft to be used (perhaps this has been the case for years, I don't really know) but if you don't know anything about the aircraft it is still just nothing more than a small aircraft. As dumb as this might sound: It appears there are some major differences between them and knowing the differences could save you some real money.

Information is power.