Extended temperature range: - 40°F to +140°F. Telephone line powered; no external power needed. Remote programming. Phone’s health status reported to central P.C. Customer-programmable call-in scheduling. Large "Palm" activation button call for help. Auto answer. Auxiliary switch to activate peripheral equipment. Three number rollover - unit dials up to three different numbers to ensure emergency calls are answered. ADA compliant features: Braille "Help" tag "Call Received" LED Indicator. Custom colors and silk-screening available. Aluminum Housing. S.M.A.R.T.