This 2-piece unit is similar to a cordless phone. There is a base station and a remote unit. The base station hooks into your phone jack and a 110v wall outlet, and has a 900mhz antenna and a cradle for charging the remote unit. Once the battery's charged in the remote unit, using it's easy. Turn the unit on, and dial as normal.
Performance is great, too.
I hooked up with my 33.6 SimpleJack and ran at app. 31600bps until my batteries died in the LX, which was over an hour. IBM touts this unit as supporting 56K modems and having battery life in excess of two hours. Range seemed to be fine, I could go anywhere in my house or backyard with no trouble. Matsushita is Panasonic's parent company, and they have a lot of experience with cordless phones, which this lil' guy basically is.