Stand-alone speech diallers that can complement any system requiring alerts of changes in system conditions. The TSD2 is also capable of temperature monitoring. The SD1 and TSD2 are stand-alone speech diallers designed to complement any system that requires alerts of changes in system conditions. The TSD2 is also capable of temperature monitoring. Messages are sent over standard PSTN line, using personalised voice messages to be transmitted to up to four (SD1) or ten (TSD2) recipients. The TSD2 also has built-in programmable outputs which can be operated remotely over PSTN. And its integrated microphone and speaker adds to the ability to listen in and speak to the site remotely. Both are complete units, with keypad and display for programming and set up.