Off net transfers on the STS can be done by pushing the "flash" key, dialing the phone number and hanging up. The only requirement is call transfer from your service provider. You can also do an unsupervised conference, push the "conf" key get an outside line and dial a telephone number then push the confrence key again. Both line keys will be lite green and the conf key will be blinking. When one of the outside partys hangup the line and conf keys will go out.