The DTR650 digital on-site portable radio delivers all the great features of the DTR550 along with managerial capabilities. The radio features operates at 900 MHz and offers enhanced communication options such as Digital One-to-Many Calling (Public Group Call and Private Group Call). It also provides enhanced performance with greater coverage up to 350,000 square feet or 30 floors (with long whip antenna) as well as longer battery life and digital audio quality that is clear and crisp within coverage areas. Advanced Message CapabilityCan transmit 25 available and 10 pre-programmed messages. Remote Update and Control FunctionsMonitors and disables units over the air. Group CallingAllows users to access up to 50 public and 20 private groups. Digital One-to-Many CallAllows other DTR radios on same group ID and channel to communicate. SMS Text MessagingComes with reception and origination information, as well as time/date stamping. Lithium-Ion BatteryGives extra-long battery lifeup to 19 hours of operation per full charge. Rugged, Compact Poly-carbonate HousingOffers comfort, with rubber over-mold. Durable DesignMeets military 810 C, D, E, and F specifications for shock, vibration, water, dust and temperature extremes. Full-Graphic Back-lit DisplayUses contrast adjustment and back-light timer and provides battery gauge. Caller IDStores recent call listup to last 10 transmissions. Unit-to-Unit Configuration Simplifies cloning operation, with via optional cable.