Mechanical temperature controller ⁄ surface-contact thermostat THERMASREG® ALTR with switching output (two-position controller). Suitable for monitoring, controlling and limiting temperatures at pipes or vessels, e.g. in connection with hot-water or underfloor heating systems. The ALTR is built as a one-step device, as an adjustable temperature controller TR (with external setting) or as an adjustable temperature monitor TW (with internal setting).